Current Electricity · Question 7

A constant voltage of 50 V is maintained between the points A and B of the circuit shown in the figure. The current through the branch CD of the circuit is: [figure]

1. 2.5 A
2. 3.0 A
3. 1.5 A
4. 2.0 A

The terminal voltage of the battery, whose emf is 10 V and internal resistance 1 , when connected through an external resistance of 4 as shown in the figure is: [figure]

1. 4 V
2. 6 V
3. 8 V
4. 10 V

A wire of length 'l' and resistance 100 is divided into 10 equal parts. The first 5 parts are connected in series while the next 5 parts are connected in parallel. The two combinations are again connected in series. The resistance of this final combination is:

1. 26
2. 52
3. 55
4. 60

Two heaters A and B have power rating of 1 kW and 2 kW, respectively. Those two are first connected in series and then in parallel to a fixed power source. The ratio of power outputs for these two cases is:

1. 1:1
2. 2:9
3. 1:2
4. 2:3

Choose the correct circuit which can achieve the bridge balance.

1. [figure]
2. [figure]
3. [figure]
4. [figure]

A uniform wire of diameter d carries a current of 100 mA when the mean drift velocity of electrons in the wire is v. For a wire of diameter d2 of the same material to carry a current of 200 mA, the mean drift velocity of electrons in the wire is

1. 4v
2. 8v
3. v
4. 2v

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