ECAT Physics Current Electricity Online Test

1. Potentiometer is more sensitive than voltmeter, because

2. If doubling the voltage across a resistor doubles the current through the resistor then

3. A certain charge liberates 0.8 g of oxygen. The same charge will liberate, how many g of silver

4. The resistance of the given conductor can be increased by

5. Resistance of wire is r ohms. The wire is stretched to double its length, then its resistance in ohms is

6. If voltage across a resistance doubles

7. The conductivity of a superconductor is

8. If the resistance in a circuit with constant voltage increases, the current will

9. Heat energy dissipated in resistors is defined as:

10. Production of heat due to an electric current following through a conductor is given by

11. Ohm’s law describes the mathematical relationship between

12. Electrical power dissipation in resistors is given by

13. The reciprocal of the resistance of a conductor is called

14. A conductor which obeys Ohm’s law is called

15. A wheat stone bridge is said to be balanced when?

16. 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

17. The wire used in rheostat, is made from

18. In a house circuit, all electrical appliances are connected in parallel to each other between the line and neutral wires to get:

19. Two resistances of 2Ω and 3Ω connected in parallel are attached to a source of 20 V. The current through 3Ω resistance is

20. The colour sequence in a carbon resistor in red, brown, orange and silver. The resistance of resistor is

21. The graphical representation of Ohms law is

22. At ordinary temperature, an increase in temperature increases the conductivity of

23. Three resistors of resistance 2, 3 and 6 ohms are connected in parallel, their equivalent resistance is

24. Power dissipated in the form of ‘V’ and ‘R’ can be determine as:

25. Electromotive force is not a force and is measured in

26. The charge on an electron is known to be 1.6 x 10¯¹⁹ coulomb. In a circuit the current flowing is 1 A. How many electrons will be flowing through the circuit in a second?

27. The passage of an electric current produces

28. What electromotive force would cause 20 A of current to flow through a 500 Ω resistor?

29. A 50 volt battery is connected across 10 ohm resistor. The current is 4.5 A. The internal resistance of the battery is

30. A car battery has e.m.f. 12 volt and internal resistance 5 x 10¯² ohm. If it draws 60 ampere current, the terminal voltage of the battery will be

31. A heater coil rated at (1000 W – 200 V) is connected to 110 volt line. What will be the power consumed?

32. Thermocouples convert heat energy into

33. Kirchhoff’s first rule is also known as

34. Terminal potential difference of a battery is greater than its emf when

35. The resistivity of constant on is Ω m is

36. Reciprocal of resistivity is called

37. The chemical changes produced during the electrolysis are due to chemical effect of

38. A wire of radius r has resistance R. If it is stretched to a wire of r/2 radius, then the resistance becomes

39. A battery of emf 12V and internal resistance 0.5 is charged by a battery charger which supplied a 132 V d.c. supply using a series resistance of 11.5. What is the terminal voltage of the battery during changing?

40. Resistance of a conductor depends upon

41. 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

42. Which one of the following causes production of heat when current is set up in a wire?

43. Two electric bulbs of 200 W and 100 W have same voltage. If R₁ and R₂ be their resistance respectively then

44. What type of temperature coefficient of resistance is thermistors?

45. If the voltage across a fixed value of resistance is increased five times, what does the current do?

46. When the resistors are connected in series, the equivalent resistance is always:

47. In a voltmeter the conduction takes place due to

48. High negative temperature coefficient thermistors are very accurate for measuring low temperature near

49. What is the current (I) in the circuit, as shown in the figure.

50. Resistively depends upon the resistance of the material of

51. Specific resistance of a wire depends upon

52. A factory gets its electrical power from a generator two miles away. The wires connecting the generator to the factory terminals have a resistance of 0.04 Ω/miles. When the generator supplies 50 Ampere to the factory, the terminal voltage at the generator is 120 Volts. A voltmeter connected to the factory terminals should then read

53. Which one is the best material for making connecting wires?

54. Photovoltaic cell converts:

55. Conventional current (l) is due to the motion of:

56. The unit of conductance of a material is

57. A ten ohm electric heater operates on a 110 V line. Calculate the rate at which it develops heat in watts:

58. Due to collisions of electrons, with the atoms of conductor, the energy transfer ultimately to the

59. Internal resistance is the resistance offered by

60. In carbon colour coded resistance, the fourth Gold ban indicates the tolerance is

61. A conducting wire is drawn to double its length. Final resistivity of the material will be:

62. Thermocouples convert:

63. Every source of current converts some non-electrical energy into

64. Two resistances of 2Ω and 3Ω connected in series are attached to a source of 20 V. The potential difference across 3Ω resistance is

65. When the temperature of a metallic conductor is increased its resistance:

66. The resistively ρ of Tungoston in Ωm is

67. In the circuit each of the three resistances has a resistance 30Ω. The potential difference across R₁ is

 

68. A (100 W, 200 V) bulb is connected to a 160 V power supply. The power consumption would be

69. The current through a metallic conductor is due to the motion of

70. The colour coded carbon resistances are made by

71. The emf is the “cause” and potential difference is its

72. Cause of heat production in a current carrying conductor is

73. When same current passes for same time through a thick and thin wire

74. Current provided by a battery is maximum when

75. The strength of an magnetic field depends upon the

76. The drifty velocity of free electrons in a metallic conductor is

77. A wire having very high value of conductance is said to be

78. Thermocouple is an arrangement of two different metals

79. The electric motors uses the effect of current passing through them is

80. The resistivity ρ of copper in Ω m is

81. Internal resistance is the resistance offered by

82. The resistance of a conductor increases with the increase in its:

83. In the figure a carbon resistor has bands of different colours on its body as mentioned in. the value of the resistance is

84. If potential difference across the conductor is one volt and one ampere current is flowing, then resistance of the conductor is:

85. The electromotive force of a battery or cell is the voltage between its terminals when:

86. As the charge flows through the conductor energy is dissipated in the form of:

87. A cell of emf 1.56 Volt is connected directly to an ammeter of resistance 0.05Ω. If the current in the circuit is 2.0A, the internal resistance of the cell is

88. In liquids and gases, the current is due to the motion of:

89. A wire of uniform area of cross-section A length La and resistance R is cut into two parts. Resistivity of each part

90. A 60 W bulb operates on 220 V supply. The current flowing through bulb is

91. The thermistors are usually made of

92. A 100 watt bulb is operated by 200 volt, the current flowing through the bulb is:

93. The potential difference between head and tail of an electric eel (fish) up to

94. The value of resistance depends upon

95. The resistivity of wire depends upon:

96. A wire of resistance 3.0 W is stretched to twice its original length, The resistance of the new wire will be

97. The potential difference across each resistance in series combination, if the resistances are different, is