ECAT Physics Current Electricity Online Test

1. The unit of conductance of a material is

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

3. The resistively ρ of Tungoston in Ωm is

4. Current provided by a battery is maximum when

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

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

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

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

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

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

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

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

13. If voltage across a resistance doubles

14. 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?

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

16. Potentiometer is more sensitive than voltmeter, because

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

18. The wire used in rheostat, is made from

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

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

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

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

23. 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

24. Resistively depends upon the resistance of the material of

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

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

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

28. Specific resistance of a wire depends upon

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

30. The colour coded carbon resistances are made by

31. Heat energy dissipated in resistors is defined as:

32. Thermocouples convert heat energy into

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

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

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

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

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

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

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

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

41. 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?

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

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

44. Photovoltaic cell converts:

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

46. 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

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

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

49. In a voltmeter the conduction takes place due to

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

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

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

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

54. The passage of an electric current produces

55. The thermistors are usually made of

56. The resistivity of wire depends upon:

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

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

59. 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

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

61. The graphical representation of Ohms law is

62. Kirchhoff’s first rule is also known as

63. 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

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

65. The conductivity of a superconductor is

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

67. Ohm’s law describes the mathematical relationship between

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

69. Electrical power dissipation in resistors is given by

70. The resistivity ρ of copper in Ω m is

71. The resistivity of constant on is Ω m is

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

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

74. Resistance of a conductor depends upon

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

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

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

 

78. The strength of an magnetic field depends upon the

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

80. Internal resistance is the resistance offered by

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

82. Thermocouple is an arrangement of two different metals

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

84. 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

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

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

87. Internal resistance is the resistance offered by

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

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

90. The value of resistance depends upon

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

92. Thermocouples convert:

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

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

95. Reciprocal of resistivity is called

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

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