Current Electricity Multiple Choice Questions and Answers for Practice
Current Electricity MCQ Questions for Practice
16. In a potentiometer of 10 wires, the balance point is obtained on the 7th wire. To shift the balance point to 9th wire, we should
Correct Answer is: increase resistance in series with the cell whose emf is to be determined.
17. In a Wheatstone bridge if the battery and galvanometer are interchanged then the deflection in galvanometer will
Correct Answer is: not change
18. In a Wheatstone‘s bridge all the four arms have equal resistance R. If the resistance of the galvanometer arm is also R, the equivalent resistance of the combination as seen by the battery is
Correct Answer is: R
19. In an experiment with potentiometer, null point with a cell is found at 240 cm. When the cell is shunted with a resistance 2 Ω, the null point becomes 120 cm internal resistance of cell is :
Correct Answer is: 2 Ω
20. In an experiment with potentiometer, null point with a cell is found at 240 cm. When the cell is shunted with a resistance 2 Ω, the null point becomes 120 cm internal resistance of cell is :
Correct Answer is: 2 Ω
21. In parallel combination of n cells, we obtain
Correct Answer is: more current
22. Kirchhoffs first and second laws for electrical circuits are consequences of:
Correct Answer is: conservation of electrical charge and energy respectively
23. Kirchoff‘s first and second laws in the electricity are the laws respectively of
Correct Answer is: Charge and energy conservation
24. Siemen is the unit of:
Correct Answer is: conductance
25. Suppose H1 is the heat generated per second in the filament of a 100 W, 250 V lamp and H2 is the heat generated in the filament of a 200 W, 250 V lamp. Then H1/H2 is equal to:
Correct Answer is: 2-Jan
26. The charge flowing in a conductor varies with time as: q = αt +1/2 βt2 + 16 γt3 Where α, β, γ are positive constants. Then the initial current (l) is given by the condition :
Correct Answer is: l = α
27. The drift velocity does not depend upon
Correct Answer is: Length of the wire
28. The electric resistance of a certain wire of iron is R. If its length and radius are both doubled, then
Correct Answer is: The resistance will be halved and the specific resistance will remain unchanged
29. The example of a non-ohmic resistance is:
Correct Answer is: diode
30. The internal resistance of a cell of emf 12 V is 5 x 10-2C Ω. It is connected across an unknown resistance. Voltage across the cell, when a current of 60 A is drawn from it, is
