CBSE
Multiple Choice QuestionsThe length of a given cylindrical wire is increased by 150%. Due to the consequent decrease in diameter the change in the resistance of the wire will be
200 %
525 %
300 %
400 %
A rod made up of metal is 1.2 m long and 0.8 cm in diameter. Its resistance is 3.5 x 10-3 Ω. Another disc made of the same metal is 2.0 cm in diameter and 1.25 mm thick. What is the resistance between the round faces of the disc?
1.35x 10-8 Ω
2.70 x 10-7 Ω
5.82 × 10-7 Ω
8.10 × 10-5 Ω
In the circuit shown in figure, if A the diode forward voltage is 0.3 V, the voltage difference between A and B is
1.3 V
2.3 V
0
0.5 V
Two batteries of emf 3V and 6 V with internal resistances 2 Ω and 4 Ω are connected in a circuit with resistance of 10 Ω as shown in figure. The current and potential difference between the points P and Q are
A galvanometer of resistance 25 Ω shows a deflection of 5 divisions when a current of 2 mA is passed through it. If a shunt of 4 Ω is connected and there are 20 divisions on the scale, then the range of the galvanometer is
1 A
58 A
58 mA
30 mA
Assertion: An electrical bulb starts glowing instantly as it is switched on.
Reason: Drift speed of electrons in a metallic wire is very large.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false
The measurement of voltmeter in the following circuit is
2.25 V
4.25 V
2.75 V
6.25 V
A meter bridge is set-up as shown, to determine an unknown resistance X using a standard 10 ohm resistor. The galvanometer shows null point when tapping-key is at 52 cm mark. The end-corrections are 1 cm and 2 cm respectively for the ends A and B. The determined value of
10.2 ohm
10.6 ohm
10.8 ohm
11.1 ohm
A body is moving along a rough horizontal surface with an initial velocity of 10 ms-1. If the body comes to rest after travelling a distance of 12m, then the coefficient of sliding friction will be
0.5
0.2
0.4
0.6
A and B are two points on a uniform ring of resistance R. The ∠ ACB = 0, where C is the centre of the ring. The equivalent resistance between A and B is
