ECAT Physics Current Electricity Online Test

1. The colour coded carbon resistances are made by

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

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

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

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

6. 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

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

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

9. 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

10. The wire used in rheostat, is made from

11. If voltage across a resistance doubles

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

13. Photovoltaic cell converts:

14. Current provided by a battery is maximum when

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

16. Kirchhoff’s first rule is also known as

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

18. Specific resistance of a wire depends upon

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

20. 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?

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

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

23. Electrical power dissipation in resistors is given by

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

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

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

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

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

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

30. The conductivity of a superconductor is

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

32. The graphical representation of Ohms law is

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

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

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

36. The passage of an electric current produces

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

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

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

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

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

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

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

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

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

46. Reciprocal of resistivity is called

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

48. Resistively depends upon the resistance of the material of

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

50. Resistance of a conductor depends upon

51. The resistivity of wire depends upon:

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

53. Internal resistance is the resistance offered by

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

55. The value of resistance depends upon

56. Thermocouples convert heat energy into

57. 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

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

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

61. The resistivity ρ of copper in Ω m is

62. The resistivity of constant on is Ω m is

63. Ohm’s law describes the mathematical relationship between

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

65. Thermocouples convert:

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

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

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

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

70. In a voltmeter the conduction takes place due to

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

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

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

 

74. 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

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

76. The unit of conductance of a material is

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

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

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

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

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

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

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

84. 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?

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

86. Internal resistance is the resistance offered by

87. Heat energy dissipated in resistors is defined as:

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

89. The strength of an magnetic field depends upon the

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

91. Thermocouple is an arrangement of two different metals

92. Potentiometer is more sensitive than voltmeter, because

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

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

95. The thermistors are usually made of

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

97. The resistively ρ of Tungoston in Ωm is