Physics ECAT Pre Engineering MCQ's Test For Full Book With Answers

Physics ECAT Pre Engineering MCQ's Test For Full Book

Sr. # Questions Answers Choice
1 Specific resistance of a wire depends upon Length Cross-section area Mass None
2 Cause of heat production in a current carrying conductor is Collisions of free electrons with one another High drift speed of free electrons Collisions of free electrons with atoms or ions of conductor High resistance value
3 In a building, there are 15 bulbs of 40 watts, 5 bulbs of 100 watts, 5 fans of 80 watts and a heater of 1 kilowatt. The voltage of the electric main is 220 volts. The minimum efficiency of the main fuse of the building will be 0.4 A 11.4 A 9.8 A 10.6 A
4 The powers of tow electric bulbs are 100 W and 200 W. Both of them are joined with 220 V mains. The ratio of resistances of their filaments will be 1 : 2 2 : 1 1 : 4 4 : 1
5 A 10 F capacitor is charged to a potential difference of 50 V and is connected to another uncharged capacitor in parallel. Now the common potential difference becomes 20 volt.The capacitance of second capacitor is 10<span style="color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 224);">μ</span>F 20<span style="color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 224);">μ</span>F 30<span style="color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 224);">μ</span>F 15<span style="color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 224);">μ</span>F
6 A certain charge liberates 0.8 g of oxygen. The same charge will liberate. how many g of silver? 108 g 10.8 g 0.8 g 108/0.8 g
7 In a voltmeter the conduction takes place due to Electrons only Holes only Electrons and holes Electrons and ions
8 A conducting wire is drawn to double its length. Final resistivity of the material will be Double of the original one Half of the original one One fourth of the original one Same as original one
9 A piece of fuse wire melts when a current of 15 ampere flows through it. With this current. If it dissipates 22.5 W, the resistance of fuse wire will be Zero 10<span style="color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 248);"><b>Ω</b></span> 1<span style="color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 248);"><b>Ω</b></span> 0.10<span style="color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 248);"><b>Ω</b></span>
10 If 2.2 kilowatt power is transmitted through a 10 ohm line at 22000 volt, the power loss in the form of heat will be 0.1 watt 1 watt 10 watt 100 watt
11 The conductivity of a superconductor is Infinite Very large Very small Zero
12 If 2.2 kilowatt power is transmitted through 1 10 ohm line at 22000 volt, the power loss in the form of heat will be 0.1 watt 1 watt 10 watt 100 watt
13 A 50 volt battery is connected across 10 ohm resistor. The current is 4.5 A. The internal resistance of the battery is Zero 0.5<span style="color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 248);"><b>Ω</b></span> 1.1<span style="color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 248);"><b>Ω</b></span> 5.0<span style="color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 248);"><b>Ω</b></span>
14 A (100 W , 200 W) bulb is connected to a 160 V power supply. The power consumption would be 64 W 80 W 100 W 125 W
15 A wire of radius r has resistance R. If it is stretched to a wire of r/2 radius, then the resistance becomes 2R 4R 16R Zero
16 Two electric bulbs of 200 W and 100 W have same voltage. If R1and R2be their resistance respectively then R<sub>1</sub>= 2R<sub>2</sub> R<sub>2</sub>= 2R<sub>1</sub> R<sub>2 </sub>=<sub> </sub>4R<sub>1</sub> R<sub>1</sub>= 4R<sub>2</sub>
17 A ten ohm electric heater operates on a 110 V line. Calculate the rate at which it develops heat in watts 1310 W 670 W 810 W 1210 W
18 5<span style="color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 248);"><b>μF</b></span> 10<span style="color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 248);"><b>μF</b></span> 3<span style="color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 248);"><b>μF</b></span> 6<span style="color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 248);"><b>μF</b></span>
19 Taking the earth to be a spherical conductor of diameter 12.8 x 103km. Its capacity will be 711<span style="color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 248);"><b>μ</b></span>F 611<span style="color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 248);"><b>μ</b></span>F 811<span style="color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 248);"><b>μ</b></span>F 511<span style="color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 248);"><b>μ</b></span>F
20 The nature of capacity of electrostatic capacitor depends on Shape Size Thickness of plates Area
21 A sheet of aluminium foil of negligible thickness is introduced between the plates of a capacitor. The capacitance of the capacitor Increases Decreases Remain unchanged Becomes infinite
22 The energy required to charge a capacitor of 5μF by connecting D.C. source of 20 KV is 10 KJ 5 KJ 2 KJ 1 KJ
23 When a dielectric material is introduced between the plates of a charged condenser the electric field between the plates Decreases Increases No change May increase or decresase
24 A capacitor of capacity 1μF is charged to 1 KV. The energy stored in J 5 0.5 0.005 50
25 If the distance between the plates of a parallel plate condenser of capacity 10μF is doubled then new capacity will be 5<span style="color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 248);"><b>μ</b></span>F 20<span style="color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 248);"><b>μ</b></span>F 10<span style="color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 248);"><b>μ</b></span>F 15<span style="color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 248);"><b>μ</b></span>F
26 The capacity of a parallel plat capacitor depends on the Type to metal used Thickness of plates Potential applied across the plates Separation between the plates
27 In a charged capacitor the energy is stored in Both in positive and negative charges Positive charges The edges of the capacitor plates The electric field between the plates
28 A condenser of capacity 50μF is charged to 10 V.The energy stored is 1.25 x 10<sup>-3</sup>J 3.75 x 10<sup>-3</sup>J 2.5 x 10<sup>-3</sup>J 5 x 10<sup>-3</sup>J
29 A metal plate of thickness half the separation between the capacitor plates of capacitance C is inserted. The new capacitance is C C/2 Zero 2C
30 A one microfarad capacitor of a TV is subjected to 4000 V potential difference. The energy stored in capacitor is 8 J 16 J 4 x 10<sup>-3</sup>J 2 x 10<sup>-3</sup>J
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