Current Electricity · Question 13

A uniform metal wire of length l has 10 resistance. Now this wire is stretched to a length 2l and then bent to form a perfect circle. The equivalent resistance across any arbitrary diameter of that circle is

1. 10
2. 5
3. 40
4. 20

The given circuit shows a uniform straight wire AB of 40 cm length fixed at both ends. In order to get zero reading in the galvanometer G, the free end of J is to be placed from B at: [figure]

1. 32 cm
2. 8 cm
3. 16 cm
4. 24 cm

The steady state current in the circuit shown below is : [figure]

1. 0.67 A
2. 1.5 A
3. 2 A
4. 1 A

The magnitude and direction of the current in the following circuit is :- [figure]

1. 0.5 A from A to B through E
2. 59 A from A to B through E
3. 1.5 A from B to A through E
4. 0.2 A from B to A through E

If the galvanometer G does not show any deflection in the circuit shown, the value of R is given by: [figure]

1. 50
2. 100
3. 400
4. 200

Resistance of a carbon resistor determined from colour codes is (22000 5\%) . The colour of third band must be :

1. Green
2. Orange
3. Yellow
4. Red

The resistance of platinum wire at 0 is 2 and 6.8 at 80 . The temperature coefficient of resistance of the wire is :

1. 3 10-3 -1
2. 3 10-2 -1
3. 3 10-10 -1
4. 3 10-4 -1

10 resistors, each of resistance R are connected in series to a battery of emf E and negligible internal resistance. Then those are connected in parallel to the same battery, the current is increased n times. The value of n is :

1. 100
2. 1
3. 1000
4. 10

As the temperature increases, the electrical resistance

1. Increases for both conductors and semiconductors
2. Decreases for both conductors and semiconductors
3. Increases for conductors but decreases for semiconductors
4. Decreases for conductors but increases for semiconductors

Two resistors of resistance, 100 and 200 are connected in parallel in an electrical circuit. The ratio of the thermal energy developed in 100 to that in 200 in a given time is

1. 1 : 2
2. 2 : 1
3. 1 : 4
4. 4 : 1