第一篇:2017年四川省廣元市中考物理試題
廣元市2017年初中學(xué)業(yè)及高中階段學(xué)校招生考試
物理
說(shuō)明: 1.全卷滿分90分,考試時(shí)間70分鐘。
2.本試題卷分為第I卷(選擇題)和第Ⅱ卷(非選擇題)兩部分,共四個(gè)大題、26個(gè)小題 3.考生必須在答題卡上答題,寫在試卷占的答案無(wú)效。選擇題必須使用2B鉛筆涂答案,非選擇題必須使用0.5毫來(lái)黑色簽字筆或鋼筆答題
4、考試結(jié)來(lái),將答題卡和試卷一并交回
第I卷選擇題(共30分)
一、選擇題(下列每小題給出的四個(gè)選項(xiàng)中,只有一個(gè)選項(xiàng)最符合題意,不選、錯(cuò)選、多選均不得分。每小題3分,共30分)1.關(guān)于聲現(xiàn)象,下列說(shuō)法正確的是
A.散學(xué)樓走道的聲控開(kāi)關(guān)是利用聲音的音調(diào)來(lái)控制電路的 B.聲音在空氣中的傳播速度與真空的傳播速度相等
C.輪船“聲吶”系統(tǒng)是利用了超聲波在水中傳播信息的特征
D.中考期間在考點(diǎn)周圍“禁止鳴笛”是為了在傳播途徑中減弱噪聲 2.下列光現(xiàn)象中,說(shuō)法正確的是
A.太陽(yáng)光通過(guò)三棱鏡形成彩色光帶是光的反射現(xiàn)象
B.小明靠近平面鏡的過(guò)程中,他在鏡中所成的像逐漸變大 c.人在岸邊看到水中的魚比魚在水中的實(shí)際位置淺 D.太陽(yáng)通過(guò)樹(shù)葉小孔所成的像是倒立、縮小的虛像
3.以下幾條摘錄出自小李在學(xué)習(xí)“內(nèi)能”一章時(shí)的學(xué)習(xí)筆記,其中不正確的是 A.擴(kuò)散現(xiàn)象能夠在固體中發(fā)生
B.分子間引力和斥力不是同時(shí)存在的 C.物體吸收熱量,溫度不一定升高
D.摩擦生熱是通過(guò)做功改變物體的內(nèi)能 4.小麗端年節(jié)家里帶助媽媽打掃衛(wèi)生,她取下白熾燈擦干凈灰塵,但發(fā)現(xiàn)白熾燈玻璃泡的下面比新燈泡變黑了一些。她通過(guò)上網(wǎng)查閱,發(fā)現(xiàn)這是燈絲發(fā)生物態(tài)變化形成的。你認(rèn)為下列關(guān)于燈絲發(fā)生物態(tài)變化過(guò)程的四個(gè)說(shuō)法,正確的是 A.先升華,后凝華
B.先升華,后凝固
C.先汽化,后液化
D.先溶化,后凝固
5.用一個(gè)導(dǎo)體制成長(zhǎng)度相等但橫截面積不同的圓柱體a和b(a和b互相連接),al橫截面積大,將它們接人電路中,如圖1所示,通過(guò)a、b電流分別為l,a、Ib兩端電壓分別為Ua、Ub,則下列說(shuō)法正確的是 A.la>Ib Ua=Ub B.Ia
6.用x,y分別表示兩個(gè)物理量,如圖2所示圖象表示這兩個(gè)物理量之間的變化規(guī)律。下列說(shuō)法正確的是
A.如果y表示物體受到的重力,則表示該物體的質(zhì)量
B.如果y表示物質(zhì)的密度,則x表示由該物質(zhì)構(gòu)的物體體積
C.如果y表示物體勻速直線運(yùn)動(dòng)的路程,則x表示該物體運(yùn)動(dòng)的時(shí)間 D.如果y表示通過(guò)導(dǎo)體的電流強(qiáng)度,則x表示該導(dǎo)體的電阻 7.下列說(shuō)法錯(cuò)誤的是
A.“天宮二號(hào)”在太空圍繞地球運(yùn)轉(zhuǎn)的過(guò)程中,機(jī)械能守恒
B.1個(gè)標(biāo)準(zhǔn)大氣壓的值與高度為76cm水銀柱產(chǎn)生的壓強(qiáng)大小相等
C.國(guó)產(chǎn)大飛機(jī)C919機(jī)翼能獲得升力,是應(yīng)用了流體流速越大的地方壓強(qiáng)越大的原理 D.放在水平桌面上的物理課本受到的重力與桌面對(duì)它的支持力是一對(duì)平衡力 8.小王在一次家庭探完活動(dòng)中,在作業(yè)本上做了如下5條記錄: ①電飯煲銘牌上標(biāo)有220V 800W 50Hz”等字樣;②使用試電筆時(shí),手必須接觸筆尾的金屬體;③電視機(jī)上安裝的動(dòng)圈式揚(yáng)聲器,其運(yùn)作原理是電磁感應(yīng);④床頭燈的開(kāi)關(guān)是串聯(lián)在電路上的
⑤體溫計(jì)的刻度范圍通常是35-42℃,分度值為1℃。你認(rèn)為小生的記錄完全正確的是 A.①②③
B.②④⑤
C.①②④
D.①③⑤
9.如圖3所示的電路,閉合開(kāi)關(guān)S,燈泡L1、L2均不發(fā)光,且電流表A和電壓表V指針均指在零刻度?,F(xiàn)將燈泡L1和L2位置對(duì)調(diào)其余元件位置不變,重新閉合開(kāi)關(guān)S時(shí),發(fā)現(xiàn)兩只燈泡仍不發(fā)光,電流表A指針仍然不動(dòng),但電壓表V的指針發(fā)生了明顯偏轉(zhuǎn)。依據(jù)上述信息可以判斷
圖3 A.燈泡L的燈絲斷了對(duì)氣的好C.電源接線處松脫D.電流表?yè)p壞了
10.如圖4所示,輕質(zhì)彈簧的下端固定在容器底部,上端與物體A連接?,F(xiàn)向容器內(nèi)注水,當(dāng)水的深度為h時(shí),彈簧長(zhǎng)度恰好為原長(zhǎng),此時(shí)物體A有1/3的體積露出水面。已知物體A體積為V,容器內(nèi)部底面積為S,水的密度為ρ水,下列計(jì)算結(jié)果正確的是 A.物體A受到的重力GA=1/3ρ水gV B.水對(duì)容器底部的壓力F=1/2ρ水ghs C.物體A的密度為pA=1/3ρ水
D.若向容器中緩慢加水直到A浸沒(méi)水中,則彈簧對(duì)A的拉力F=1/3ρ水gv
Ⅱ卷非選擇題(共60分)
二、填空與作圖題(11-17小題每空1分,18-19小題每圖2分,共20分)11.一束光AO射向平面鏡,光線AO與鏡面的夾角如圖5所示,則反射角的大小為_(kāi)_______現(xiàn)在城市里很多高樓大廈采用玻璃幕墻作裝飾,當(dāng)強(qiáng)烈的太陽(yáng)光照射到玻璃幕墻時(shí),就會(huì)發(fā)生________反射,造成“光污染”。
12小兵全家利用國(guó)慶節(jié)假期自駕游,汽車行駛過(guò)程中因轉(zhuǎn)彎而導(dǎo)致身體傾斜,小兵向父母解釋,這是由于__________原因造成的。在高速路上,小兵看見(jiàn)一個(gè)路牌如圖6甲所示,小兵從路牌處開(kāi)始觀察到汽車速度計(jì)指針一直指在圖6乙所示位置,則小兵經(jīng)過(guò)_________分鐘到達(dá)廣元。
13.汽車汽油機(jī)是由四個(gè)沖程的不斷循環(huán)來(lái)保證連續(xù)工作的,其中由機(jī)械能轉(zhuǎn)化為內(nèi)能的是_______沖程。已知汽油的熱值為4.6×107J/Kg , 2Kg汽油完全燃燒時(shí)釋放的熱量為_(kāi)____J,已知汽車防凍液比熱容為4.2×103J/(Kg.℃),防凍液從90℃冷卻到20℃的過(guò)程中,放出的熱量為2.94×106J,則汽車防凍液的質(zhì)量為_____kg 14.1820年,丹麥物理學(xué)家______在課堂上做實(shí)驗(yàn)時(shí)發(fā)現(xiàn)了電流的磁效應(yīng)。電流也具有熱效應(yīng),20年后的1840年,英國(guó)物理學(xué)家焦耳最先精確地確定了電流產(chǎn)生的熱量跟電流、電阻和________的關(guān)系,家用電風(fēng)扇工作時(shí),電動(dòng)機(jī)同時(shí)也要發(fā)熱,一臺(tái)標(biāo)明220V44W”的電風(fēng)扇正常工作10分鐘,電流產(chǎn)生的熱量為______J(已知電動(dòng)機(jī)線圈電阻為2Ω)。15.用如圖7所示的滑輪組在5s內(nèi)將重G=240N的物體勻速向上提起3m,拉力F=150N,這個(gè)滑輪組的機(jī)械效率是_____,如果忽略繩重和摩擦,動(dòng)滑輪自重為_____
16.一只彈簧測(cè)力計(jì)和一根細(xì)線,要求測(cè)量小石塊的密度。小強(qiáng)將小石塊掛在彈簧測(cè)力下端,示數(shù)如圖8甲所示,再將小石塊浸沒(méi)在水中,示數(shù)如圖8乙所示,則小石塊浸沒(méi)在水中時(shí)受到的浮力為______N,小石塊的密度為______g/cm3(已知水的密度為1.0×103kg/m3,g取10N/kg)。
17.兩個(gè)電子元件A和B串聯(lián)后接入電路,流過(guò)元件的電流與其兩端電壓關(guān)系如圖9所示當(dāng)流過(guò)元件A的電流為0.4A時(shí),元件A、B兩端電壓之比為______A、B兩元件消耗的總 3 功率為_______
18.如圖10所示,工人用一根硬棒以O(shè)為支點(diǎn),想在A點(diǎn)施加最小的力撬動(dòng)石頭,請(qǐng)畫出最小動(dòng)力F1的示意圖和阻力F2的力臂L2
19.小蘭用如圖11所示的電路探究電生磁現(xiàn)象。當(dāng)滑動(dòng)變阻器的滑片向A端滑動(dòng)時(shí),通電螺線管的磁性減弱。請(qǐng)你用筆畫線代替導(dǎo)線將實(shí)物圖補(bǔ)充完整,并標(biāo)出通電螺線管的N極
圖10
圖11
三、實(shí)驗(yàn)探究題(每空2分,共24分)20.小敏研究某固體物質(zhì)的熔化實(shí)驗(yàn)結(jié)束后,撤去酒精燈并開(kāi)始記錄溫度計(jì)示數(shù)和時(shí)間,作出了如圖12所示圖像。根據(jù)圖像信息可知:該物質(zhì)的凝固點(diǎn)是___℃,凝固過(guò)程用了__min
圖12 21.小華用光具座研究凸透鏡成像規(guī)律,按圖13評(píng)警完畢在光屏上得到蠟燭燭焰清晰的像
圖13(1)保持蠟燭、凸透鏡、光屏位置不變,小華用不透光的紙板遮住凸透鏡上半部分則在光屏上觀察到的像是________(填選項(xiàng)前的字母)。A.燭焰的上半部分,亮度
B.燭焰的下半部分,亮度變暗 C.完整的燭焰,亮度變暗
D完整的獨(dú)焰亮度不變
(2)保持凸透鏡位置不變,將蠟燭與光屏位置對(duì)調(diào),光屏上也能得到燭焰清晰的像__________(選填“照相機(jī)”、“投影儀”、“放大鏡”)就是根據(jù)這種成像原理設(shè)計(jì)的。
22.小興同學(xué)要測(cè)量盒裝純牛奶的密度。將天平放在水平桌面上,把游碼移至標(biāo)尺左零刻度線上,完全靜時(shí)發(fā)現(xiàn)指針情形如圖甲所示,為了使天平橫梁平衡,應(yīng)將平衡螺母向___調(diào)節(jié)。用天平測(cè)出空燒杯質(zhì)量為28.6g,向燒杯中倒入適量純牛奶,測(cè)量燒杯和純牛奶總質(zhì)量的示數(shù)如圖14乙所示,再將燒杯中純牛奶全部倒入量筒中,示數(shù)如圖14丙所示,則純牛奶的密度約為_____kg/m3
23.如圖15甲所示是小張“探究物體的動(dòng)能與哪些因素有關(guān)”的實(shí)驗(yàn)裝置。
(1)小張讓大小不同的實(shí)心鋼球球從同一斜面上相同的高度處由靜止?jié)L下,在水平面上運(yùn)動(dòng)并推動(dòng)木塊移動(dòng),是為探究動(dòng)能大小與_____的關(guān)系
(2)同班同學(xué)小紅發(fā)現(xiàn),木塊被鋼球撞擊后移動(dòng)的距離沒(méi)有其他同學(xué)的明顯,認(rèn)為是木塊太重導(dǎo)致滑動(dòng)摩擦力過(guò)大的原因造成。為了驗(yàn)證猜測(cè),小紅設(shè)計(jì)了如圖15乙所示究滑動(dòng)摩擦力與壓力大小關(guān)系”的實(shí)驗(yàn),當(dāng)接觸面粗糙程度不變,用彈簧測(cè)力計(jì)拉動(dòng)木塊勻速直線運(yùn)動(dòng)時(shí),通過(guò)多次實(shí)驗(yàn)得到了表格中的相關(guān)數(shù)據(jù),請(qǐng)你根據(jù)表中數(shù)據(jù)幫她分析并得出,滑動(dòng)摩擦力f與壓力F之間的數(shù)量關(guān)系式為________
24.小琳想知道一只標(biāo)明“220V40W”白熾燈不發(fā)光時(shí)的燈絲電阻有多大,她設(shè)計(jì)了圖16甲所示電路原理圖,并找來(lái)器材動(dòng)手實(shí)驗(yàn)。
(1)按照如圖甲所示連接電路,檢查無(wú)誤后閉合開(kāi)關(guān)S,調(diào)節(jié)滑動(dòng)變阻器R,電壓表和電流表的示數(shù)分別如圖乙、丙所示,此時(shí)燈絲電阻為____Ω
(2)小琳設(shè)想如果沒(méi)有電壓表,能否再找一只電流表和一個(gè)定值電阻來(lái)代替電壓表于是她設(shè)計(jì)了如圖16丁所示電路原理圖(R0為阻值已知的定值電阻),連接電路并檢查無(wú)誤后閉合開(kāi)關(guān)S,調(diào)節(jié)滑動(dòng)變阻器R,當(dāng)電流表A1、A2示數(shù)分別為I
1、l2時(shí),燈絲電阻RL=(用R0、I1、I2表示測(cè)量結(jié)果)(3)小琳用公式R=U2/P計(jì)算出燈泡正常發(fā)光時(shí)的電阻為1210Ω,比(1)中測(cè)量的電阻大得多,請(qǐng)你幫助小琳給出合理解釋:______________________________________ 5(4)小琳根據(jù)圖16乙和丙的示數(shù),計(jì)算了此時(shí)燈泡實(shí)際消耗的電功率與額定功率相差_____W
四、解答題(解答應(yīng)寫出必要的文字說(shuō)明、公式、演算步驟、數(shù)值和單位。每小題8分,共16分)25.未來(lái)的廣元將是全國(guó)綠色生態(tài)康養(yǎng)城市之一,提倡大家低碳出行,電動(dòng)汽車比燃油汽車低碳環(huán)保并且能源利用率高,是今后交通工具的發(fā)展方向。某款新型家用四輪電動(dòng)汽車質(zhì)量為0.6t,每個(gè)輪胎與地面接觸面積為20cm2,汽車蓄電池提供電壓150V,電動(dòng)機(jī)正常之流為10A使汽車獲得240N的牽引力,保證汽車以18km/h的速度在水平路面上勻速行駛,g取590)求:(1)汽車靜止時(shí)對(duì)地面的壓強(qiáng)。
(2)汽車勻速行駛5min克服摩擦阻力所做的功。(3)電動(dòng)機(jī)正常工作時(shí),電能轉(zhuǎn)化為機(jī)械能的效率。
26.小軍家里有一款高、低溫兩檔電烤爐,他查看使用說(shuō)明書,收集到一些信息如下:額定電壓220V,低溫檔電功率88W,高溫檔功率1980W,電路原理圖如圖所示,R1,R2代表兩根電熱絲,S2為溫溫控開(kāi)開(kāi)關(guān)。根據(jù)上述信息,解答下列問(wèn)題:
(1)在高溫檔正常工作時(shí),電路中的總電流多大?(2)在低溫檔正常工作1.5h消耗多少度電能?電熱絲R1的電阻多大?(3)若電熱絲R2燒毀了,要使電路恢復(fù)正常工作,小軍用兩根“220V550W”的相同電熱絲替代R2,你認(rèn)為小軍的做法能否滿足要求(請(qǐng)你用計(jì)算結(jié)果回答)。
第二篇:2018年四川省廣元市中考物理試題
2018年四川省廣元市中考物理試卷
一、選擇題
1.關(guān)于聲現(xiàn)象的描述,下列說(shuō)法正確的是()A.圖中超聲波清洗眼鏡,說(shuō)明聲可以傳遞信息
B.同 C.振動(dòng)產(chǎn)生的 D.需要介質(zhì) 圖中能從不同樂(lè)器中分辨出小提琴的聲音主要是因?yàn)轫懚炔粓D中敲擊鼓面,鼓面上的泡沫顆粒跳動(dòng),說(shuō)明聲音是由物體的圖中逐漸抽出玻璃罩內(nèi)的空氣,鬧鐘音量減弱,說(shuō)明聲音的傳播不2.在如圖所示的各事例中,屬于熱傳遞改變物體內(nèi)能的是()
A.搓手,手變暖和
B.加熱,水溫升高 C.壓活塞,硝化棉燃燒
D.滑滑梯,臀部發(fā)熱
3.隨著科技實(shí)力的不斷提升,我國(guó)逐漸由一個(gè)航天大國(guó)向航天強(qiáng)國(guó)邁進(jìn)。2017年4月,中國(guó)自主研制的首艘貨運(yùn)飛船“天舟一號(hào)”在海南文昌航天發(fā)射場(chǎng)使用“長(zhǎng)征七號(hào)”運(yùn)載火箭發(fā)射,并與“天宮二號(hào)”空間站順利完成自動(dòng)交會(huì)對(duì)接,如圖所示。此時(shí)說(shuō)“天宮二號(hào)”是靜止的,選取的參照物是()
A.“天宮二號(hào)” B.太陽(yáng) C.“長(zhǎng)征七號(hào)” D.“天舟一號(hào)” 4.如圖是某人眼睛看物體時(shí)的成像示意圖。則他的視力情況,及矯正需要選用的透鏡分別是()
A.遠(yuǎn)視眼 凸透鏡 B.遠(yuǎn)視眼 凹透鏡 C.近視眼 凸透鏡 D.近視眼 凹透鏡 5.下列做法符合安全用電常識(shí)的是()A.有金屬外殼的家用電器,金屬外殼必須接地 B.雷雨時(shí),不要在開(kāi)闊地行走,可以躲在大樹(shù)下 C.使用試電筆時(shí),手不要接觸筆尾金屬體,以免觸電 D.空氣開(kāi)關(guān)“跳閘”,一定是發(fā)生了短路,立即重新合上
6.習(xí)近平主席指出,要像愛(ài)護(hù)生命一樣愛(ài)護(hù)我們的環(huán)境,所以低碳環(huán)保已經(jīng)逐漸成為全社會(huì)的共同理念。我市積極響應(yīng)這一理念,在各區(qū)縣投放了大量的共享單車。下列關(guān)于共享單車的說(shuō)法正確的是()
A.車把是一個(gè)省力杠桿
B.車座的面積較大是為了增大壓強(qiáng) C.輪胎表面凹凸不平的花紋可以減小摩擦
D.停止用力蹬腳踏板,車也會(huì)繼續(xù)前進(jìn)一段距離是因?yàn)檐囀艿綉T性
7.用如圖所示的工具提升相同重物G,(不計(jì)摩擦,不計(jì)繩、滑輪和杠桿重)最省力的是()
A.B.C.D.8.下列關(guān)于熱現(xiàn)象的描述中正確的是()A.墻內(nèi)開(kāi)花墻外香,這是擴(kuò)散現(xiàn)象 B.液體很難被壓縮,因?yàn)榉肿娱g存在斥力 C.水和煤油升高相同的溫度,水吸收的熱量較多 D.濕衣服涼在通風(fēng)的地方能夠加快它的水分蒸發(fā)
9.在央視2套“是真的嗎”欄目中,一位網(wǎng)友演示了一把如圖所示的“銅絲琴”;他將一根張緊的銅絲兩端與揚(yáng)聲器接通,銅絲旁邊放置一塊磁鐵,用手指撥動(dòng)銅絲,就能使揚(yáng)聲器發(fā)聲,演奏出優(yōu)美的樂(lè)曲。這個(gè)聲音是()
A.振動(dòng)的銅絲直接發(fā)出的 B.空氣振動(dòng)而發(fā)出的
C.通電銅絲在磁場(chǎng)中受力振動(dòng)而發(fā)出的
D.振動(dòng)的銅絲切割磁感線產(chǎn)生感應(yīng)電流使揚(yáng)聲器發(fā)出的
10.根據(jù)交通部門統(tǒng)計(jì),我國(guó)每年的交通事故中很多都是酒駕所造成的,所以現(xiàn)在交警加大了對(duì)酒駕的打擊力度。圖甲是酒精濃度測(cè)試儀的原理圖,R為酒精氣體傳感器,其阻值隨酒精氣體濃度的變化曲線如圖乙,R0為定值電阻,電源電壓不變,當(dāng)被檢測(cè)者酒精濃度增加時(shí)()
A.電流表的示數(shù)減小 B.電壓表的示數(shù)增大 C.電路總電阻增加 D.電路總功率減小
二、填空與作圖題 11.改革開(kāi)放40年來(lái),人民的生活水平得到了很大的提高,很多家庭都用上了電冰箱。冰箱冷藏室內(nèi)壁常常會(huì)結(jié)冰,這是_______現(xiàn)象,致冷劑在冰箱冷凍室的管子里面_______吸熱,從而使冷凍室溫度降低。(填物態(tài)變化名稱)12.為了減少污染,很多地方都大力推廣使用清潔能源,罐裝液化石油氣也是一種清潔能源。如果每一罐內(nèi)裝有液化氣10kg,則這些液化氣完全燃燒放出的熱量為_(kāi)______J(液化氣的熱值為4.2×10J/kg)。液化石油氣屬于_______能源。(選填“一次能源”或“二次能源”)
13.張薇期末成績(jī)考得好,爸爸獎(jiǎng)勵(lì)她一個(gè)新手機(jī),張薇發(fā)現(xiàn)手機(jī)電池上標(biāo)有“電壓3.7V,容量3500mAh”的字樣,則它充滿電后存儲(chǔ)的電能為_(kāi)______J,經(jīng)查,該手機(jī)的待機(jī)電流為20mA,則該手機(jī)最長(zhǎng)待機(jī)時(shí)間為_(kāi)______h。14.如圖所示,將一薄木尺的長(zhǎng)度用多層報(bào)紙緊密地覆蓋在水平桌面上(桌面與報(bào)紙之間幾乎沒(méi)有空氣),已知報(bào)紙的上表面積為0.21m.則大氣對(duì)報(bào)紙上表面的壓力為_(kāi)______N;在木尺右端快速施加豎直向下的力F,要將報(bào)紙掀開(kāi),則力F至少為_(kāi)______N(假設(shè)報(bào)紙不破損,報(bào)紙對(duì)木尺的壓力全部作用在木尺最左端,大氣壓取1.0×10Pa,報(bào)紙和薄木尺的重力忽略不計(jì))。
527
15.根據(jù)已給出的入射光和出射光,請(qǐng)?jiān)诜娇騼?nèi)畫出合適的透鏡。
16.如圖所示,用細(xì)線將小球懸掛在豎直墻壁上,請(qǐng)畫出小球所受重力的示意圖。
三、實(shí)驗(yàn)探究題
17.如圖是小薇同學(xué)“探究平面鏡成像特點(diǎn)”的裝置:用玻璃板作平面鏡,將其豎立在水平面上,在其下面垂直地放一把刻度尺,兩支完全相同的蠟燭A、B豎立于玻璃板兩側(cè)的刻度尺上。點(diǎn)燃玻璃板前面的蠟燭A,移動(dòng)蠟燭B直到與蠟燭A的像完全_______。從刻度尺上可以發(fā)現(xiàn),此時(shí)蠟燭A到鏡面的距離與它的像到鏡面的距離_______。
18.小蘇同學(xué)的物理興趣小組準(zhǔn)備探究“彈簧彈性勢(shì)能的大小與什么因素有關(guān)”。他們猜想:彈簧彈性勢(shì)能可能與彈簧長(zhǎng)度變化量、彈簧螺紋圈直徑、彈簧的材料等因素有關(guān)。
他們的實(shí)驗(yàn)裝置如圖所示,把彈簧放在水平面上,其左端固定在墻上,AO等于彈簧原長(zhǎng),水平面O點(diǎn)左側(cè)光滑,右側(cè)粗糙。將物體M從O點(diǎn)壓縮彈簧到P點(diǎn),然后由靜止釋放,當(dāng)物體M運(yùn)動(dòng)到O點(diǎn)與彈簧分開(kāi),最終運(yùn)動(dòng)到Q點(diǎn)靜止。請(qǐng)補(bǔ)充完成他們的探究過(guò)程:
(1)彈簧彈性勢(shì)能的大小是通過(guò)_______來(lái)衡量的。(2)探究彈簧彈性勢(shì)能與彈簧長(zhǎng)度變化量的關(guān)系,應(yīng)該選用_______(選填“相同”或“不同”)彈簧進(jìn)行實(shí)驗(yàn),并先后改變_______之間的距離,測(cè)出OQ的距離,重復(fù)實(shí)驗(yàn),測(cè)量多組數(shù)據(jù)并記錄。
(3)小蘇的實(shí)驗(yàn)小組經(jīng)過(guò)多次實(shí)驗(yàn)得出了結(jié)論。在上面的實(shí)驗(yàn)中,他們運(yùn)用到了轉(zhuǎn)換法和_______兩種物理思想方法。
19.如圖甲,是張勇實(shí)驗(yàn)小組在探究“電流與電阻的關(guān)系”時(shí)的電路圖,電源電壓恒為6V.電壓表、電流表無(wú)損壞,有阻值為5Ω、10Ω、20Ω、30Ω、40Ω定值電阻5個(gè)。
(1)根據(jù)圖甲,用筆畫線代替導(dǎo)線連接完成圖乙的實(shí)物圖。______(2)實(shí)驗(yàn)過(guò)程中,需要改變定值電阻,觀察電流的變化,為了科學(xué)地得出實(shí)驗(yàn)結(jié)論,當(dāng)每次更換電阻后,都要移動(dòng)滑動(dòng)變阻器的滑片,此時(shí)眼睛應(yīng)注意觀察_______(選填序號(hào))。
A.變阻器滑片 B.電壓表 C.電流表 D.電源
(3)某次實(shí)驗(yàn),更換電阻R,合上開(kāi)關(guān)后,電壓表示數(shù)為0,電流表示數(shù)正常,其原因可能是_______。
(4)在老師的引導(dǎo)下,他們將5次實(shí)驗(yàn)數(shù)據(jù)描繪在圖丙中。圖中陰影部分“面積”表示的物理量是_______(選填序號(hào))。A.電流B.電壓C.電阻D.電功率
(5)實(shí)驗(yàn)中,他們選擇下列哪個(gè)滑動(dòng)變阻器最合適_______(選填序號(hào))。A.10Ω 0.5A B.50Ω 0.5A C.50Ω 1A D.200Ω 1A(6)請(qǐng)你用平滑曲線將圖丙中5個(gè)點(diǎn)連接起來(lái),觀察圖象你可以得出實(shí)驗(yàn)結(jié)論:當(dāng)電壓一定時(shí),導(dǎo)體中的電流與導(dǎo)體的電阻_______。
四、解答題
20.關(guān)于深海的探究,對(duì)一個(gè)國(guó)家的國(guó)防和經(jīng)濟(jì)建設(shè)都有很重要的意義,我國(guó)在這一領(lǐng)域的研究也處于世界領(lǐng)先水平。如圖甲是我們自行研制的水下智能潛航器,其外形與潛艇相似,相關(guān)參數(shù)為:體積2m、質(zhì)量1500kg,最大下潛深度5000m,最大下潛速度10km/h(不考慮海水密度變化,密度ρ取1.0×10kg/m,g取10N/kg)。求:
(1)某次執(zhí)行任務(wù),當(dāng)潛航器下潛到最大深度時(shí)所受的海水壓強(qiáng)。(2)潛航器以最大下潛速度勻速豎直下潛至最大深度所用的時(shí)間。
(3)潛航器任務(wù)完成后,變?yōu)樽灾貢r(shí)靜止漂浮在海面上,此時(shí)露出海面體積。(4)當(dāng)潛航器漂浮在海面時(shí),由起重裝置將其勻速豎直吊離海面。起重裝置拉力的功率隨時(shí)間變化的圖象如圖乙所示,圖中P3=3P1.求t1時(shí)刻起重裝置對(duì)潛航器的拉力。(不考慮水的阻力)
21.張強(qiáng)媽媽買了一個(gè)新的電飯煲,張強(qiáng)從說(shuō)明書中,得知下表中的信息,工作電路圖如圖甲所示,S1為溫控開(kāi)關(guān),加熱電阻R1和R2的阻值不隨溫度變化。求:
(1)電飯煲在“保溫”狀態(tài)下正常工作時(shí),通過(guò)電飯煲的電流;(2)電阻R2的阻值;
(3)某周末的晚飯時(shí),張強(qiáng)想利用自家電能表(如圖乙)測(cè)量家庭電路的實(shí)際電壓。于是他關(guān)閉了家中其它所有用電器,只讓電飯煲在“蒸煮”狀態(tài)下工作,觀察到電能表的轉(zhuǎn)盤在1min內(nèi)轉(zhuǎn)了50轉(zhuǎn)。求家庭電路的實(shí)際電壓。
第三篇:2010年四川省廣元市中考英語(yǔ)試題
2010年四川省廣元市中考英語(yǔ)試題(滿分120分考試時(shí)間120分鐘)
第I卷(選擇題共98分)第一部分基礎(chǔ)知識(shí)運(yùn)用(共兩節(jié)滿分40分)
第一節(jié):單項(xiàng)選擇(共20小題;每小題1分滿分20分)
從下列各題的A、B、C三個(gè)選項(xiàng)中選出能填入題中空白處的最佳選項(xiàng)。
1.—Is this your dictionary?
—No ____________ is in my bag.A.mine
B.me
C.my
2.—Hello, may I speak to Mr Green?
—I'm sorry.I think you have the wrong ____________.A.card
B.number
C.address
3.—What do you usually do after supper, Sally?
—Play
piano.A.a
B./
C.the
4.—Cindy, could you help me?
—Wait a moment.I ____________.A.am cooking the dinner
B.was doing my homework
C.do some reading
5.—How can I improve my spoken English, Mr Zhang?
—You should try to talk____________ English in class.A.with
B.in
C.about 6.一 ____________
—Pretty good!
A.How's it going
B.Where is it going
C.Where is it
7.—Mum, I'm a little tired.—Why not stop ____________
A.have a rest
B.to have a rest
C.having a rest
8..—I'm worried about Kitty.She hasn't come back yet.—Don't be afraid, dear.There will be ____________ happening to her.A.something
B.anything
C.nothing 9.一____________ swim in the river alone.It's dangerous.A.Let's
B.Don't
C.Not
10.一Where's Jim, dear?
—He ____________ to the supermarket to buy some food for dinner.A.has gone
B.has been
C.was going
11.—Sam, let's go camping after the exam.— ____________
.A.That's right
B.That sounds good
C.No, I can't go
12.—Can you come to see the movie with us this evening? —I'd like to,but I ____________ do my homework first.A.must
B.have to
C.mustn't
13.I can't see the blackboard clearly.Could you help ____________ the lights?
A.turn off
B.turn up
C.turn on
14.—How do you like the curry beef?
—Oh, it tastes ____________
A.good
B.well
C.badly
15.He is really.__________ lucky.kind people have sent money to help him A.Hundred
B.Hundreds
C.Hundreds of
16.We both have black eyes and black hair, although my hair is _________ than hers.A.short
B.shortest
C.shorter ____________.we brought our umbrellas and raincoats.So we didn't get wet.A.Luckily
B.Unluckily
C.Lucky
18.If it ____________this weekend, we'll have a football match.A.doesn't rain
B.won't rain
C.isn't rain
19.I want to be young and beautiful.And I don't mind______ young people think of me.A.how
B.what
C.that
20.一Should friends be the same as Dale? 一No.In fact, I like to have friends_________ are different from me, Mr Zhao.A.what
B.which
C.who
第二節(jié)完形填空(共20小題;每小題1分滿分20分 先通讀下面短文讀懂大意后再?gòu)暮竺娓黝}所給A、B、c三個(gè)選項(xiàng)中選出可以填入文中相應(yīng)空白處的最佳選項(xiàng)。
A Dear Jack,I had a very unusual experience on Sunday.I can 21____ believe it!Do you want to 22 ____ what it was? 23______ around ten o'clock in the morning, I was walking down the street 24_____a UFO landed right in front of me.You can imagine 25______ how 0strange it was!26______alien got out and walked down Center Street.I followed it to see 27______ it was going and I was very 28 ______ when it went into a souvenir shop.While it was 29 ______ the souvenirs , the assistant called the police.Before the police 30_____, the alien left the shop and then visited the Museum of Flight.While the alien was in the museum, I called the TV station isn't that amazing!
Ted
21.A.hard
B.never
C.hardly
22.A.know
B.listen
C.see
23.A.In
B.On
C.At
24.A.before
B.when
C.after
25.A.what
B.why
C.how
26.A.The
B.An
C.A
27.A.where
B.how
C.why
28.A.surprised
B.surprise
C.surprising 29.A.looking for
B.looking at
C.looking over
30.A.got
B.reached
C.arrived
B Hi, boys and girls!Do you know how to be a healthy kid? Here are some 31______ you should follow.First, eat different foods,especially fruit and vegetables.You may have a favorite, 32______you must eat something different.If you eat different foods, you will probably 33______more nutrients(營(yíng)養(yǎng))your body needs.Second, drink water and milk as often as possible.When you're really 34______ cold water is the best.Third,“l(fā)isten” to your body.How do you feel when you are full? When you are eating feel how your body feels.When you are full, eating too 35______ will not make you feel comfortable and will make you 36______.Fourth, limit(限制)screen time.Screen time is the time you watch TV, DVDs and videos, or using computers.37______ is good to take more exercise such as playing basketball, 38______ and so on.You can't watch TV for 39______than two hours a day.Fifth, be active.One thing you should do is to know which activity you like best.Find ways to be active 40______ Follow these rules and you can be a healthy-kid.31.A.foods
B.advice
C.rules
32.A.but
B.and
C.or 33.A.drink
B.eat
C.get
34.A.full
B.thirsty
C.hungry
35.A.little
B.much
C.many 36.A.thin
B.fat
C.smart
37.A.It
B.That
C.This 38.A.swim
B.swimming
C.to swim
39.A.more
B.over
C.less
40.A.everyday B.every year
C.every day
第二部分閱讀理解(共25小題;每小題2分滿分50分)
閱讀下面短文從每題所給A、B、C三個(gè)選項(xiàng)中選出正確答案。
A Monday to Saturday Football BIG HITS CINEMA
TOURNAMENT(聯(lián)賽)Movies every night at 7
Final : Saturday Actor of the week
pm Jack Dean
Will the local team make it
Harry Potter children's show
all the way to the end? Saturday at 2 pm
Find out more by calling ——330333——
——3226060——
Mother's DAY BIG SALE
Give Your TV a Break!From10 am to 3 pm
TV-Turnoff Week June 22—28 EVERYTHING 50% OFF(降價(jià))Join 10 thousand families to do these things
Make your dreams
Fall in love with
together this week come true.Save time
things you can
.take a walk and money.afford.listen to music
Visit us at Hongqi Supermarket.talk about dreams If you want to take part in, call 3203232 or mail to TV Break@ 163.com.41.If you want to know some movie information, you can call______.A.3226060
B.330333
C.3203232
42.When is the final of the football tournament?
A.Friday.B.Saturday.C.Sunday.43.A dress is ¥300 at Hongqi Supermarket.If your mother buys it at 12 o'clock on Mother's Day, she should pay ______.A.¥150
B.¥300
C.¥50
44.In the TV-Turnoff Week, people can ______
.A.talk about dreams
B.take a walk
C.A and B
45.Which of the following is TRUE?
A.The big sale on Mother's Day is in the afternooa
B.You can send emails if you want to join the 10 thousand families.C.You can see movies in the morning.B
A rich man once walked along the road and saw an old man digging in his field(地)On the ground lay a young tree, ready to be planted.The rich man asked the old man,”What kind of trees are you planting there, my good man?“ “This is a ginkgo(銀杏)”sir” he said.”A ginkgo tree? Why? May I ask you how old you are?” “I am 70.“ “What?” cried the rich man,”You're 70.You are planting a very young tree now and it'll take years to give fruit.You certainly can't live long enough to get any fruit from this tree.” The old man looked up and then he said with a smile.“Tell me, sir.Did you eat ginkgo fruit when you were a boy?” “Sure” the rich man answered.”Who planted the ginkgo?“The old man asked.“I don't know.” ”The people before us planted trees for us to enjoy the fruit and I am doing the same for the people after me.“ The rich man was quiet for a moment and said, ”You are right, my good man.You are doing the right thing.Thank you very much.”
46.What was the old man doing when the rich man saw him?
A.Laying a tree.B.Digging to plant a tree.C.Walking along the road.47.How did the rich man feel when he knew the man was planting a ginkgo tree?
A.Happy.B.Angry.C.Surprised.48.Why did the old man plant a ginkgo? A.He wanted to eat ginkgo fruit.B.He wanted to do something for the people after him.C.He wanted to thank the people before him.49.Which of the following is TRUE?
A.The rich man hadn't eaten any ginkgo fruit when he saw the old man.B.The old man liked ginkgo very much.C.The rich man learned something from the old man.50.What is the best title(標(biāo)題)for the story?
A.Do some things for the people after us
B.A ginkgo tree
C.Plant a ginkgo
C Why do students go to school? What do they do at school? Students learn their lessons in class.They sit in the classroom listening to the teacher.This is a way of learning.Is this the only way for students to learn? Of course not.There is another way to learn.That is, students can teach themselves.For example, if you cannot remember something when you are doing your homework, what will you do? You can look at your book to get the answer.How to teach yourself? The first thing you must do is reading.Read something you are interested ia The second is that you must ask yourself questions.A clever student is usually good at asking questions.The third is to answer the questions yourself by thinking hard, by reading booksand sometimes by asking other people.These are the ways of teaching yourself.If you keep doing like these for a long time, you are sure to have great success in your study.51.Why do students go to school?
A.They go to teach themselves.B.They go to learn their lessons.C.They go to do their homework.52.What can students do if they can't remember something when doing their homework? A.Give it up.B.Ask the teacher.C.Read books to find the answer.53.What should you do first when you teach yourself?
A.Read books.B.Ask questions.C.Answer questions.54.According to the article, can we ask others for help when teaching ourselves?
A.Yeswe can.B.Nowe can't.C.We don't know.55.What may be the best title(標(biāo)題)for the article?
A.How to teach yourself
B.Teach yourself—an important way of learning
C.The way of learning
D “Depend on yourself” is what nature says to every man.Both parents and teachers can help you.Friends still can help you.But all these people only help you to help yourself.There have been many great men in history.When they were young, many of them were very poor, and had no uncles,aunts, or friends to help them some of them even lost parents and had to support themselves.At that time, schools were few and not very good.They could not depend on them for education.They tried their best to learn something and never gave up till they became well-known.A famous teacher in England used to tell his pupils, “I cannot make worthy(有價(jià)值的)men of you, but I can help you make men of yourselves.“ But these days some young men don't try their best to make themselves valuable(有價(jià)值的)to the human beings.Some even play computer games to kill time all day.If they see their weak points and change their ways, they can be successful.They are nothing now, and will be nothing as long as they live unless they take the advice of their parents and teachers, and depend on themselves.56.Why did some great men succeed though they were poor in their childhood?
A.Because they did their best and never gave up.B.Because they got good education.C.Because they got lots of help.57.According to the famous English teacher, what can a teacher do?
A.He can make his pupils full of courage(勇氣)and strength(力量)B.He can help his pupils with everything.C.He can make his pupils worthy men.58.What will happen if young people depend on their efforts(努力)?
A.They will be famous all over the world.B.They will succeed in their lives.C.They will never need any help.59.Which of the following is NOT true?
A.The writer thinks playing computer games is a waste of time.B.The writer thinks highly of the people depending on themselves.C.The writer is a famous teacher.60.What's the best title(標(biāo)題)for the passage?
A.Listen to the nature
B.Self-confidence
C.Man should depend on himself
E
Once a little boy named Tom always felt lonely and unhappy.One day he decided to meet love.He started off with some food and drinks in the early morning.When he passed through a small park, he saw an old woman watching some flowers.She looked a little hungry.He gave her a sandwich.She gave him a smile and ate it.The smile was very beautiful.He wanted to see it again.So he gave her another sandwich.She smiled at him once again.Tom was very happy and sat down beside her.They sat there for a long time, eating and smiling, but said nothing.When it grew dark Tom decided to go home.After he had gone a few steps, he turned around, ran back and gave the old woman a hug(擁抱), And she gave him the biggest smile ever.When Tom came back home his mother was amazed at the joy(快樂(lè))on his face.”Tom, why are you so happy?“ asked the mother.”I had lunch with love, and she has the most beautiful smile in the world.”Also the old woman's daughter was amazed at her mother's pleasure.“Mum, what has made you so happy?“ asked the daughter.”I ate some sandwiches with love and he is much younger than I expected," the old woman answered.61.What was the old woman doing when Tom met her?
A.She was watching some flowers.B.She was waiting for Tom.C.She was looking for food.62.Why did Tom gave her another sandwich?
A.Because he wanted to see the smile again.B.Because she wanted to eat some again.C.Because she was still hungry.63.When did Tom get the biggest smile?
A.After he gave her another sandwich.B.After he hugged the old woman.C.Before he began to leave.64.How were Tom's mother and the old woman's daughter? A.The mother was careful but the daughter was careless.B.The daughter was careful but the mother was careless.C.Both of them were very careful.65.What can we learn from the passage?
A.Tom didn't find love.B.Tom found love.C.Both Tom and the old woman found love.第三部分口語(yǔ)運(yùn)用共8小題;每小題1分滿分8分
從對(duì)話后的方框中選擇適當(dāng)?shù)倪x項(xiàng)補(bǔ)全對(duì)話。
A A: Hi,can I help you?
B: Yes, please.I want to join a club.A: OK.66
B:Li Hua.A: 67 A What club do you want to join?
B A music club.A 68 B I have learned it for 5 years and I love it very much.A 69 B Yes? I do.It's lihua@163.com.AGreat.Thanks a lot.B Thank you.A.How long have you learned it?
B.What's your name, please? C.How old are you?
D.Do you have an email address? B A Hello.How are you? B 70 AWhat's the matter? 71 B: NoI(xiàn) don't have a cold, but I have a really bad headache.A:I see.How about your throat? Does it feel sore? B 72 But my back and neck are sore.A:Do you have a stomachache? B:Nomy stomach's okay.73 A:WellI(xiàn) think you're stressed out.You should go home and relax.A.I feel terrible, doctor!
B.But I don't feel hungry.C.Do you have a cold?
D.Noit doesn't.第II卷(非選擇題共22分)
第四部分寫?yīng)踩?jié),滿分22分) 第一節(jié)單詞拼寫(滿分5分)
根據(jù)上下文及漢語(yǔ)提示填寫出句中所缺單詞。
74.—How's the weather in China? —It's cold and ______
(多風(fēng)的).75.Thank you for your last letter.Here are some______(照片)of me and my twin sister Liu Ying.76.At the beginning she spoke too ______(快)and I couldn't understand every word.77.I know you are arriving next Sunday.Now let me______(告訴)you the way to my house.78.—I'm doing a survey about ______(傲)sports.Can I ask you some questions? —Sure.第二節(jié)短文填空(滿分5分)根據(jù)短文內(nèi)容和首字母提示,把文中所缺單詞填寫在短文后的橫線上。Tiger Woods is a famous professional golfer.He was born in the United States in 1975.When he was only ten months old, he began to learn h______ 79 to play golf from his father.In 1978when Tiger was three years oldhe was on his first TV show.He played golf with some famous people and he surprised everyone.Between the ages of 8 and 16Tiger Woods learned a 1.______80 about golf.He won his first championship in these years.In 1994Tiger became a s______ 81 of Stanford University.He won 10 golf championships while he was studying at the university.In 1996Tiger became a professional golfer and made more m______ 82 He was very rich and famous though he was very young.Now he has m______ 83 fans and is a model for many young people.79 ______
80.______ 81.______
82.______ 83.______
.第三節(jié)書面表達(dá)(滿分12分) 自廣元成為國(guó)家級(jí)旅游城市以來(lái)每年前來(lái)廣元的外國(guó)游客越來(lái)越多。為了方便外國(guó)游客 打造廣元旅游品牌某主管部門擬制作英文“廣元旅游指南”?,F(xiàn)請(qǐng)你按以下要點(diǎn)提示寫 一份廣元簡(jiǎn)介。
1.位于川北歷史悠久
2.名勝古跡眾多交通便利 3.人民友好特產(chǎn)豐富
4.國(guó)家級(jí)旅游城市旅游休閑勝地。
參考詞匯:交通便利have transport facilities 特產(chǎn) special local product
國(guó)家級(jí)state-level
注意①可適當(dāng)發(fā)揮以使行文連貫 ②詞數(shù)70左右。
第四篇:河北省2018中考物理試題
一、選擇題(10~19題為單選題,每小題的四個(gè)選項(xiàng)中,只有一個(gè)選項(xiàng)符合題意,每小題2分,20~22小題為多選題,每小題的四個(gè)選項(xiàng)中,有兩個(gè)或者兩個(gè)以上的選項(xiàng)符合題意,每小題3分,全部選對(duì)的得3分,選對(duì)但不全的得2分,有錯(cuò)選或不選的不得分)10.生活中的下列做法合理的是
A.醫(yī)院里用紫外線燈滅菌 B.用濕布擦拭正在發(fā)光的臺(tái)燈 C.經(jīng)常用鋼絲球擦洗鋁鍋 D.發(fā)霉的大米多淘洗幾次食用 l1.下列事實(shí)不能作為相應(yīng)觀點(diǎn)的證據(jù)的是 A.塵土飛揚(yáng),說(shuō)明分子是運(yùn)動(dòng)的
B.電解水得到氫氣和氧氣,說(shuō)明分子是可分的
C.氣體被壓縮后體積發(fā)生了較大變化,說(shuō)明氣體分子間的距離大
D.將兩個(gè)干凈平整的鉛柱緊壓在一起會(huì)結(jié)合起來(lái),說(shuō)明分子間存在引力 12.歸類整理是學(xué)習(xí)的一種重要方法。下列歸類正確的是 A.氯、碘、汞都是非金屬元素
B.醋酸、硝酸鉀、二氧化硅都是化合物 C.鐵、木頭、玻璃都是熱的良導(dǎo)體 D.太陽(yáng)能、風(fēng)能、核能都是可再生能源 13.下列應(yīng)用與原理對(duì)應(yīng)不正確的是 A.防毒面具——活性炭吸附有毒物質(zhì) B.利用聲吶探知海洋深度——回聲定位 C.油鍋著火時(shí)用鍋蓋蓋滅——隔絕空氣
D.船閘——流體中流速越大的位置壓強(qiáng)越小
14.分析圖5所示實(shí)驗(yàn)現(xiàn)象得出的結(jié)論中,合理的是
A.甲:燒杯內(nèi)壁有水珠生成,說(shuō)明甲烷中含有碳元素和氫元素
B.乙:摩擦后的塑料梳子能吸引碎紙屑,說(shuō)明紙屑與梳子帶同種電荷 C.丙:試管中無(wú)明顯現(xiàn)象,說(shuō)明CO2與NaOH溶液沒(méi)有發(fā)生化學(xué)反應(yīng) D.丁:彈簧測(cè)力計(jì)讀數(shù)相同,說(shuō)明使用定滑輪不省力但可以改變力的方向 15.下列數(shù)值最接近實(shí)際情況的是 A.洗澡水的溫度約為70 ℃ B.一部手機(jī)的質(zhì)量約為1 kg C.普通居民樓每層高約為5 m D.聲音在空氣中的傳播速度約為340 m/s 16.下列有關(guān)聲和電磁波的說(shuō)法正確的是 A.它們的傳播都需要介質(zhì) B.它們都可以傳遞信息和能量
C.人聽(tīng)到的聲音大小只跟發(fā)聲體的振幅有關(guān)
D.開(kāi)會(huì)時(shí)把手機(jī)調(diào)為靜音是在傳播過(guò)程中減弱噪聲 17.下列與物態(tài)變化相關(guān)的說(shuō)法正確的是
A.出汗時(shí)吹風(fēng)扇感覺(jué)涼快,是因?yàn)轱L(fēng)降低了室溫 B.石蠟和冰的熔化一樣,都吸熱但溫度保持不變 C.冬天人呼出的“白氣”和露珠的形成原理相同
D.因?yàn)檠┑男纬蛇^(guò)程中吸收熱量,所以下雪時(shí)天氣變冷 18.下列說(shuō)法正確的是
A.靜止的物體可能受到摩擦力的作用
B.越高的攔河大壩,水的重力勢(shì)能一定越大
C.火車進(jìn)站時(shí)需提前減速,是因?yàn)榛疖囀艿綉T性作用
D.地面上滾動(dòng)的小球越滾越慢,是由于小球的慣性越來(lái)越小
19.在“探究凸透鏡成像的規(guī)律”實(shí)驗(yàn)中,蠟燭、凸透鏡和光屏的位置如圖6所示,燭焰在光屏上恰好成一清晰的像。則下列說(shuō)法正確的是
A.照相機(jī)應(yīng)用了這一成像規(guī)律
B.蠟燭燃燒一段時(shí)間后,光屏上的像會(huì)向下移
C.蠟燭不動(dòng),將透鏡移至35 cm處,移動(dòng)光屏可能得到倒立的清晰像 D.更換一個(gè)焦距小的凸透鏡,只移動(dòng)透鏡仍可在光屏上得到清晰的像 20.下列有關(guān)電與磁的說(shuō)法正確的是
A.磁感線是用來(lái)形象描述磁場(chǎng)的,并不真實(shí)存在 B.懸吊著的小磁針靜止時(shí)N極指向地理南極附近C.法拉第在世界上第一個(gè)發(fā)現(xiàn)了電與磁之間的聯(lián)系
D.電磁繼電器是利用電磁鐵來(lái)控制工作電路的一種開(kāi)關(guān) 21.水平桌面上放置一底面積為S的薄壁圓筒形容器,內(nèi)盛某種液體,將質(zhì)量分別為mA、mB、mc,密度分別為?A、?B、?c的均勻?qū)嵭男∏駻、B、C放入液體中,A球漂浮,B球懸浮,C球下沉,如圖7所示,它們所受的浮力分別為FA、FB、Fc。下列選項(xiàng)正確的是
A.若mA = mB = mc,則FA = FB > Fc
B.將C球截去部分后,剩余部分可能上浮 C.只取出A球,容器中液面的高度降低了
D.三球放入液體前后,液體對(duì)容器底部的壓強(qiáng)變化了
22.如圖8所示,電源電壓不變,a、b、c為電流表或電壓表。只閉合S1時(shí),a表無(wú)示數(shù),b表有示數(shù)。S1、S2都閉合時(shí),滑片P向右滑動(dòng),c表的示數(shù)不變。下列判斷正確的是 A.a表是電壓表
B.先閉合開(kāi)關(guān)S1,再閉合S2,電路中的總電流變大
C.只閉合S1,P向右移動(dòng),R2兩端的電壓變化量與電流變化量的乘積大于其電功率的變化量
D、開(kāi)關(guān)均閉合,電路的總功率為P1;若將c表?yè)Q成另一種電表,再閉合S1、S2,電路的總功率為P2,則P2 > P1
二、填空及簡(jiǎn)答題(本大題共9個(gè)小題;每空1分,共31分)23.小明一家外出旅游,出門時(shí)電能表示數(shù)為,回來(lái)時(shí)為,這期間消耗了______度電。這些電能可使標(biāo)有“220 V 25 W”的燈泡正常工作______h。24.小明在平靜的湖邊看到“云在水中飄,魚在云上游”的現(xiàn)象?!霸圃谒酗h”是小明以_________為參照物看到“云”在水中運(yùn)動(dòng)的現(xiàn)象?!棒~在云上游”是魚通過(guò)水面的_________形成的虛像和云在水面的__________形成的虛像同時(shí)出現(xiàn)的現(xiàn)象。
25.一臺(tái)起重機(jī)在10 s內(nèi)將重為3 600 N的貨物勻速提高了4 m,起重機(jī)做的有用功是______J。若起重機(jī)做的額外功是9 600 J,則機(jī)械效率是_______,起重機(jī)的功率是_________W。
26.有如圖9所示的兩套相同裝置,分別在兩個(gè)燃燒皿中放入質(zhì)量相同的不同燃料,點(diǎn)燃后加熱質(zhì)量相等的同種液體,通過(guò)比較燃料,_______________(選填“燃燒相同時(shí)間”或“全部燃燒”)后溫度計(jì)示數(shù)的變化,來(lái)判斷兩種燃料的熱值的大小。燃料燃燒,____________轉(zhuǎn)化為內(nèi)能,用比熱容_________的液體可以使實(shí)驗(yàn)現(xiàn)象更明顯。(實(shí)驗(yàn)中液體沒(méi)有沸騰)
27.圖10所示,在一個(gè)配有活塞的厚透明筒里放一小團(tuán)硝化棉,把活塞迅速下壓,壓縮空氣__________,使筒內(nèi)空氣的內(nèi)能增大,溫度升高,觀察到硝化棉___________。上述改變物體內(nèi)能的方式與發(fā)燒時(shí)用冷毛巾給頭部降溫改變物體內(nèi)能的方式_____(選填“相同”或“不相同”)。
29.理化知識(shí)在生產(chǎn)、生活中有著廣泛的應(yīng)用。(1)燒水時(shí)易生水垢的水,屬于___水。
(2)人體攝入____元素不足或過(guò)量均會(huì)導(dǎo)致甲狀腺疾病。(3)保險(xiǎn)絲(鉛銻合金)比組成它的純金屬的熔點(diǎn)_______。(4)用洗潔精除去油污,是由于洗潔精對(duì)油污有________。
(5)尼龍手套、玻璃茶杯、純棉桌布中,主要用有機(jī)合成材料制成的是________。
三、實(shí)驗(yàn)探究題(本大題共4個(gè)小題:第32小題4分,第33小題6分,第34、35小題各7分,共24分)32.制作簡(jiǎn)易氣壓計(jì),觀察大氣壓隨高度的變化。
(1)如圖14所示,在玻璃瓶中倒入適量紅色的水,將插有玻璃管的橡皮塞塞緊瓶口,紅水升到玻璃管一定的高度,但高度不夠,你應(yīng)_______________________,使水上升到瓶口以上適當(dāng)位置,制成了簡(jiǎn)易氣壓計(jì)。
(2)將簡(jiǎn)易氣壓計(jì)從四樓移到一樓過(guò)程中,發(fā)現(xiàn)玻璃管內(nèi)水柱_______________,說(shuō)明______________________________。
(3)小明將簡(jiǎn)易氣壓計(jì)放在陽(yáng)光下,過(guò)一會(huì)兒,他發(fā)現(xiàn)玻璃管內(nèi)水柱發(fā)生了變化,這一現(xiàn)象說(shuō)明,簡(jiǎn)易氣壓計(jì)的測(cè)量結(jié)果會(huì)受到_________________________影響。33.探究杠桿的平衡條件。
(1)杠桿兩端的螺母作用是_______________。
(2)小明用如圖15所示裝置,進(jìn)行實(shí)驗(yàn)并收集了下表中的數(shù)據(jù),分析數(shù)據(jù)可知,杠桿的平衡條件是____________________________________________。
(3)小明又用如圖16所示裝置進(jìn)行實(shí)驗(yàn)。請(qǐng)?jiān)趫D中畫出拉力F的力臂,彈簧測(cè)力計(jì)的讀數(shù)應(yīng)是_______N。(一個(gè)鉤碼重0.5 N)
(4)如圖17所示,小紅實(shí)驗(yàn)時(shí)在一平衡杠桿的兩端放上不同數(shù)量的相同硬幣,杠桿仍在水平位置平衡。她用刻度尺測(cè)出L1和L2,則2L1____(選填“>”“<” 或“=”)3L2。
【拓展】探究了杠桿的平衡條件后,小紅對(duì)天平上游碼的質(zhì)量進(jìn)行了計(jì)算。她用刻度尺測(cè)出L1和L2(如圖18所示),則游碼的質(zhì)量為_(kāi)___g。
34.用如圖19所示的裝置探究“電流通過(guò)導(dǎo)體產(chǎn)生的熱量與電流的關(guān)系”。相同燒瓶?jī)?nèi)裝滿了煤油。
(1)燒瓶中裝入的煤油是________(選填“導(dǎo)體”或“絕緣體”)。(2)請(qǐng)根據(jù)實(shí)物電路,在虛線框內(nèi)畫出對(duì)應(yīng)的電路圖。
(3)為達(dá)到實(shí)驗(yàn)?zāi)康?,選用的兩電阻絲R1與R2的阻值應(yīng)________,通過(guò)R1的電流______通過(guò)R2的電流。
(4)通電一段時(shí)間后,乙燒瓶中玻璃管內(nèi)液面上升的高度較大。說(shuō)明_____________________________ __________________________________________________。
(5)小紅用如圖20所示的裝置,進(jìn)一步探究“電流通過(guò)導(dǎo)體產(chǎn)生的熱量與電流的關(guān)系”。經(jīng)多次實(shí)驗(yàn)測(cè)量,收集實(shí)驗(yàn)數(shù)據(jù),繪制了燒瓶中玻璃管內(nèi)液面上升的高度h與電流I的關(guān)系圖象。根據(jù)焦耳定律可知,圖21中能正確反映h-I關(guān)系的是____________。
【拓展】用Q=IRt可以計(jì)算電流通過(guò)任何用電器產(chǎn)生的熱量,能用Q=UIt計(jì)算通過(guò)任何用電器產(chǎn)生的熱量嗎?請(qǐng)用實(shí)例說(shuō)明原因。
_________________________________________________________________________________________________________________________________________。
四、計(jì)算應(yīng)用題(本大題共3個(gè)小題;第36小題5分,第37小題6分,第38小題7分,共18分。解答時(shí),要求有必要的文字說(shuō)明、公式和計(jì)算步驟等,只寫最后結(jié)果不得分)37.實(shí)心圓柱體甲和長(zhǎng)方體乙分別放置在水平地面上,甲的密度為0.6×104 kg/m3,質(zhì)量為12 kg,底面積為4×10?2 m2;乙的質(zhì)量為5.4 kg,邊長(zhǎng)分別為0.1 m、0.2 m 0.3 m。(g取10 N/kg)(1)求乙的密度。
(2)求甲直立時(shí)對(duì)水平地面的壓強(qiáng)。
(3)若在甲的上方水平截去一段并疊放在乙的正上方后,甲剩余圓柱體對(duì)水平面的壓強(qiáng)恰好等于此時(shí)乙對(duì)水平地面壓強(qiáng)的最小值,求甲截去的高度。
38.如圖28所示,電源電壓不變,小燈泡L的額定電壓為10 V,滑動(dòng)變阻器R1的規(guī)格為“10 Ω 1 A”。閉合開(kāi)關(guān),當(dāng)滑片P置于距左端三分之一處,燈泡正常發(fā)光,電流表指針滿偏,電表表盤如圖29所示。
(1)求燈泡的額定功率和電源電壓。
(2)用定值電阻R2替代小燈泡,再將另一電壓表V2接入電路,其它部分電路連接不變。閉合開(kāi)關(guān),當(dāng)滑片P置于某一位置時(shí),兩個(gè)電壓表指針偏轉(zhuǎn)的角度相同,且表V2示數(shù)大于表V1的示數(shù),兩種電表指針偏轉(zhuǎn)角度之比為2:1。求R2可能的阻值。
第五篇:2011中考物理試題 新材料
201
1年中考物理分類匯編認(rèn)識(shí)新材料
25.(2011陜西)(3分)納米是長(zhǎng)度單位。圖
示為世界上最小的發(fā)電機(jī)——納米發(fā)電機(jī)。納米發(fā)電機(jī)主要依
靠氧化鋅等晶體材料在機(jī)械壓力作用下產(chǎn)生電壓,實(shí)現(xiàn)將
能轉(zhuǎn)化為能,為納米器件提供電力。
【答案】10-9機(jī)械電
【解析】1nm=10m。納米發(fā)電機(jī)在機(jī)械壓力作用下產(chǎn)生電壓,是將機(jī)械能轉(zhuǎn)化為電能。
1.(2011陜西)悉尼科技大學(xué)的研究小組研發(fā)了一種獨(dú)特的復(fù)合材料——石墨紙,如圖所示。
其成分以石墨為主,薄如紙張,比鋼要堅(jiān)硬10倍且輕巧,還可以回收再利用。未來(lái)應(yīng)用非常廣泛。下列說(shuō)法錯(cuò)誤的是
A. 與同體積的鋼相比,石墨紙的質(zhì)量較小
B. 與鋼相比,石墨紙的硬度較大
C. 石墨紙是一種環(huán)保材料
D. 石墨紙是絕緣體,不易導(dǎo)電。
【答案】D
【解析】由于石墨是導(dǎo)體,所以石墨紙是導(dǎo)體,易導(dǎo)電,選項(xiàng)D的說(shuō)法錯(cuò)誤。
3.(2011北京)下列用品中,通常情況下屬于絕緣體的是B
A.金屬勺B.瓷碗C.鉛筆芯D.鐵釘
9.(2011河南)筆記本電腦外殼多采用優(yōu)質(zhì)的ABS工程塑料,這主要是利用廠這種塑料的A
A.硬度大B.磁性強(qiáng)C.密度大D.導(dǎo)電性好
11.(2011揚(yáng)州)2010年諾貝爾物理學(xué)獎(jiǎng)授予兩位研究石墨烯材料的教授.石墨烯是一種神奇的物質(zhì),是人類至今發(fā)現(xiàn)的厚度最薄、強(qiáng)度最高的材料.針對(duì)這一發(fā)現(xiàn)同學(xué)們提出了以下幾個(gè)問(wèn)題,你認(rèn)為較有價(jià)值且可探究的問(wèn)題是D
A.“石墨烯為什么很???”
B。“如何提取石墨烯這種物質(zhì)?”
C.“石墨烯在生活中有什么用處?”
D.“石墨烯的強(qiáng)度與石墨烯的厚度、面積有什么關(guān)系?”
8、(2011莆田)當(dāng)溫度降低到一定程度時(shí),某些物質(zhì)的電阻會(huì)變?yōu)榱?,這種物質(zhì)叫做超導(dǎo)體。電流通過(guò)超導(dǎo)體時(shí)不發(fā)熱,因此超導(dǎo)體的應(yīng)用十分廣泛。假如有室溫環(huán)境中的超導(dǎo)體,可用它來(lái)制作(D)
A、家用保險(xiǎn)絲B、白熾燈燈絲
-9/
5C、電熱絲D、輸電導(dǎo)線
12.(2011雞西)我國(guó)新研制的殲20飛機(jī)具有一定的隱身功能,主要是由于飛機(jī)的機(jī)身
(A)
A.對(duì)電磁波有吸收作用B.對(duì)電磁波有反射作用
C.對(duì)超聲波有吸收作用D.對(duì)超聲波有反射作用
11.(2011德州)下列實(shí)例與所利用的物質(zhì)的屬性不相符的是A
A.熱水壺的手柄常用膠木制作,是因?yàn)槟z木的導(dǎo)熱性好
B.電線的內(nèi)芯常用鋁或銅制作,是因?yàn)殂~或鋁的導(dǎo)電性好
C.眼鏡框常用金屬鈦制作,是因?yàn)殁伒难诱剐院湍透g性好
D.機(jī)器的底盤常用鈦制作,是因?yàn)殁伒拿芏缺容^大
4.(2011淮安)納米材料是由納米顆粒經(jīng)過(guò)特殊制備得到的。室溫下外形相同的納米銅比普通銅可多拉長(zhǎng)50倍而不斷裂的事實(shí),表明納米銅具有較好的C
A.導(dǎo)電性B.導(dǎo)熱性C.延展性D.彈性
“霸王舉鼎”是宿遷市的標(biāo)志性雕塑之一.這段歷史故事已被搬上熒
屏.劇中大鼎的道具最適合用下列哪種材料制作 D
A.石頭B.鐵C.銅D.泡沫塑料
(2011衡陽(yáng))石墨烯——改變世界的神奇新材料
一片碳,看似普通,厚度為單個(gè)原子,卻使兩位科學(xué)家海姆和諾
沃肖洛夫贏得2010諾貝爾物理學(xué)獎(jiǎng)。這種全新材料名為“石墨
烯”。
石墨烯不僅“最簿、最強(qiáng)”,作為電導(dǎo)體,它和銅有著一樣出色的導(dǎo)電性;作為熱導(dǎo)體,它比目前任何其他材料的導(dǎo)熱效果都好。利用石墨烯,科學(xué)家能夠研發(fā)一系列具有特殊性質(zhì)的新材料。比如,石墨烯晶體管的傳輸速度遠(yuǎn)遠(yuǎn)超過(guò)目前的硅晶體管,因此有希望應(yīng)用于全新超級(jí)計(jì)算機(jī)的研發(fā);石墨烯還可以用于制造觸摸屏、發(fā)光板,甚至太陽(yáng)能電池。如果和其他材料混合,石墨烯還可用于制造更耐熱、更結(jié)實(shí)的電導(dǎo)體,從而使新材料更薄、更輕、更富有彈性,從柔性電子產(chǎn)品到智能服裝,從超輕型飛機(jī)材料到防彈衣,甚至未來(lái)的太空電梯都可以以石墨烯為原料。因此其應(yīng)用前景十分廣闊。
(1)這種新材料屬于____(填“導(dǎo)體”或“絕緣體”)。導(dǎo)體
(2)石墨烯應(yīng)用于超級(jí)計(jì)算機(jī)的研發(fā),是因?yàn)椋撸撸撸撸撸撸撸撸撸摺J┚w管的傳輸速度遠(yuǎn)遠(yuǎn)超過(guò)目前的硅晶體管
第4題圖
(3)石墨烯的應(yīng)用領(lǐng)域十分廣泛,請(qǐng)你從材料中找出兩例_____________。柔性電子產(chǎn)品、智能服裝、超輕型飛機(jī)材料、防彈衣、太空電梯等
27.(2011鹽城)(10分)閱讀短文,回答問(wèn)題:
力傳感器在電子秤中的應(yīng)用
電子秤所使用的測(cè)力裝置是力傳感器.
常見(jiàn)的一種力傳感器由彈簧鋼和應(yīng)變片組成,其結(jié)構(gòu)示意圖如圖甲所示.彈簧鋼右端固定,在其上、下表面各貼一個(gè)相同的應(yīng)變片.若在彈簧鋼的自由端施加向下的作用力F,則彈簧鋼發(fā)生彎曲,上應(yīng)變片被拉伸,下應(yīng)變片被壓縮.力越大,彈簧鋼的彎曲程度越大.
應(yīng)變片結(jié)構(gòu)如圖乙所示,其中金屬電阻絲的阻值對(duì)長(zhǎng)度變化很敏感.給上、下金屬電阻絲提供相等且大小不變的電流,上應(yīng)變片兩引線間電壓為U1,下應(yīng)變片兩引線間電壓為U2,傳感器把這兩個(gè)電壓的差值U(U=U1-U2)輸出,用來(lái)反映力F的大小.
金屬電阻絲的阻值隨溫度會(huì)發(fā)生變化,其變化情況如圖丙所示.為消除氣溫變化對(duì)測(cè)量精度的影響,需分別在上、下應(yīng)變片金屬電阻絲與引線之間串聯(lián)一只合適的電阻,進(jìn)行溫度補(bǔ)償.串聯(lián)合適的電阻后,測(cè)量結(jié)果不再受溫度影響.
自 由端 甲 乙
第27題圖丙
t/℃
(1)這種力傳感器是將力的大小轉(zhuǎn)換為▲(電流/電壓)的裝置.
(2)外力F增大時(shí),下列說(shuō)法正確的是▲.
A.上、下應(yīng)變片金屬電阻絲電阻都增大
B.上、下應(yīng)變片金屬電阻絲電阻都減小
C.上應(yīng)變片金屬電阻絲電阻減小,下應(yīng)變片金屬電阻絲電阻增大
D.上應(yīng)變片金屬電阻絲電阻增大,下應(yīng)變片金屬電阻絲電阻減小
(3)傳感器輸出的電壓U隨外力F增大而▲.
(4)進(jìn)行溫度補(bǔ)償時(shí),應(yīng)給上金屬電阻絲串聯(lián)阻值隨溫度升高而▲的電阻,下金屬電阻
絲串聯(lián)阻值隨溫度升高而▲的電阻.
(5)如果未進(jìn)行溫度補(bǔ)償,自由端受到相同的力F作用,該傳感器下應(yīng)變片兩端的電壓U
2冬天比夏天▲(大/小).
27.本題10分
(1)電壓(2分)(2)D(2分)(3)增大(2分)
(4)減?。?分)減?。?分)(5)?。?分)
8..(2011廣東)硅、鍺等半導(dǎo)體材料的導(dǎo)電能力比銅、鐵等金屬的導(dǎo)電能力____(選填“強(qiáng)”或“弱”)。某些物質(zhì)在溫度很低時(shí),電阻變?yōu)開(kāi)___,這就是超導(dǎo)現(xiàn)象。如果能制造出常溫下的超導(dǎo)體,它可以在下列哪些情境得到應(yīng)用____(選填序號(hào))。
①用作電吹風(fēng)的電熱絲②用作白熾燈的燈絲③用作輸電線纜
弱零③
4.(2011沈陽(yáng))材料科學(xué)的發(fā)展正在影響著我們的生活,下列關(guān)于材料應(yīng)用的說(shuō)法中正確的是(D)
A.保險(xiǎn)絲是利用半導(dǎo)體材料制成的B.利用超導(dǎo)材料做電熱絲,電熱絲會(huì)更熱
C.利用鎢做燈絲,是因?yàn)殒u的熔點(diǎn)低
D.試電筆外殼是用塑料制成的,因?yàn)樗墙^緣材料
9.(2011連云港)完成太空飛行的航天器在穿過(guò)稠密的大氣層返回地球的過(guò)程中,外殼與
空氣劇烈摩擦,溫度能達(dá)到幾千攝氏度;為了能使航天器克服“熱障”安全返回地面,航天技術(shù)專家給航天器穿上用新型陶瓷材料制成的“外衣”。主要是利用這種材料的(C)
A.絕緣性好B.密度大
C.耐高溫和隔熱性好D.延展性好
7.(2011無(wú)錫)下列實(shí)例中,材料的選用與描述的物理屬性不相符的是C
A.電線的線芯用銅制成,是因?yàn)殂~的導(dǎo)電性好
B.房屋的天窗用玻璃制成,是因?yàn)椴AУ耐腹庑院?/p>
C.水壺的把手用膠術(shù)制成,是因?yàn)槟z木的導(dǎo)熱性好
D.劃玻璃的刀刃用金剛石制成,是因?yàn)榻饎偸挠捕却?/p>
22.(2011年杭州市)科學(xué)家設(shè)想利用道路來(lái)收集太陽(yáng)能進(jìn)行發(fā)電,供電動(dòng)汽車和路燈使用。方法是在路基上先鋪設(shè)覆蓋有太陽(yáng)能電池的水泥板,再在太陽(yáng)能電池上覆蓋透明的玻璃作為路面,這個(gè)設(shè)想要能實(shí)際使用,對(duì)玻璃的選擇,下列哪一項(xiàng)不是主要需考慮的D
A.玻璃表面粗糙程度B.玻璃強(qiáng)度C.玻璃顏色D.玻璃的隔音效果
10.(2011年福州市)石墨烯又稱單層墨,它僅由一層碳原子組成,具有許多奇特的屬性,包括極強(qiáng)的拉力,優(yōu)良的導(dǎo)電性和導(dǎo)熱性,硬度最大,熔點(diǎn)超過(guò)3000℃等,這種高新材料有可能代替硅成為新的半導(dǎo)體材料。發(fā)現(xiàn)石墨烯的兩位俄裔科學(xué)家因此獲2010年諾貝爾物理學(xué)獎(jiǎng)。根據(jù)石墨烯的特性,你認(rèn)為石墨烯不能用來(lái)制成(D)
A.高壓輸電線B.堅(jiān)韌的防彈衣
C.發(fā)光二極管D.保溫隔熱材料
10.(2011臨沂)下列說(shuō)法正確的是B
A.機(jī)械鐘表中的發(fā)條可以儲(chǔ)存時(shí)鐘運(yùn)轉(zhuǎn)所需要的能量,主要是由于制成發(fā)條的材料具有很好的延展性
B.橡膠是一種很好的彈性材料,用橡膠輪胎可以大大減輕汽車的震動(dòng)與顛簸
C.銅是一種很好的導(dǎo)體,是因?yàn)樗哂休^高的硬度
D.銀錠具有很高的硬度,所以可以將其拉成絲
5.(2011年廣州市初中畢業(yè))以下說(shuō)法正確的是
A.半導(dǎo)體具有良好的導(dǎo)電性能B.超導(dǎo)體是一種電阻很大的材料
C.納米技術(shù)是大尺度范圍內(nèi)的科學(xué)技術(shù) D.超導(dǎo)材料用于輸送電力可以降低電能損耗
4.(2011溫州)科學(xué)家最新研制了一款微型無(wú)人偵察機(jī)——“峰鳥(niǎo)”。為了減輕其質(zhì)量,該偵察機(jī)的材料應(yīng)具有的特點(diǎn)是()
A.硬度高
B.熔點(diǎn)低
C.密度小
D.導(dǎo)熱性好
答案:C
1.(2011蘇州)下列常見(jiàn)的物品中能被磁鐵吸引的是B
A.銅鑰匙B.鐵釘C.塑料尺D.橡皮