ECAT Physics Current Electricity Online Test

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

2. The thermistors are usually made of

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

4. Current provided by a battery is maximum when

5. Ohm’s law describes the mathematical relationship between

6. Heat energy dissipated in resistors is defined as:

7. The unit of conductance of a material is

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

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

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

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

12. Thermocouple is an arrangement of two different metals

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

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

15. Electrical power dissipation in resistors is given by

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

17. 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

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

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 value of resistance depends upon

21. 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?

22. The conductivity of a superconductor is

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

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

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

 

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

27. In a voltmeter the conduction takes place due to

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

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

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

31. Specific resistance of a wire depends upon

32. 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

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

34. 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

35. The resistivity of constant on is Ω m is

36. Internal resistance is the resistance offered by

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

38. The resistivity of wire depends upon:

39. Resistively depends upon the resistance of the material of

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

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

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

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

44. Resistance of a conductor depends upon

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

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

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

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

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

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

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

52. Photovoltaic cell converts:

53. Reciprocal of resistivity is called

54. Kirchhoff’s first rule is also known as

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

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

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

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

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

60. The resistively ρ of Tungoston in Ωm is

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

62. The passage of an electric current produces

63. Thermocouples convert:

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

65. 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?

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

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

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

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

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

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

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

73. Potentiometer is more sensitive than voltmeter, because

74. Thermocouples convert heat energy into

75. Internal resistance is the resistance offered by

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

77. The resistivity ρ of copper in Ω m is

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

79. If voltage across a resistance doubles

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

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

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

83. The strength of an magnetic field depends upon the

84. 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

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

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

87. The colour coded carbon resistances are made by

88. The graphical representation of Ohms law is

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

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

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

92. 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

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

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

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

96. The wire used in rheostat, is made from

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