In a balanced Wheatstone bridge, the current in the galvanometer is zero. It remains zero when:

[1] battery emf is increased.

[2] all resistances are increased by 10 ohms.

[3] all resistances are made five times.

[4] the battery and the galvanometer are interchanged.

1. Only [1] is correct

2. [1], [2] and [3] are correct

3. [1], [3] and [4] are correct

4. [1] and [3] are correct

When a battery is getting charged:

1. the voltage drop across its internal resistance is zero.

2. the terminal potential difference is less than its emf.

3. the terminal potential difference is more than its emf.

4. its terminal potential difference is zero.

Which of the following wiring diagrams can be used to experimentally determine R using Ohm's law? Assume the voltmeter and the ammeter to be ideal.

1. 

2.

3. 

4. 

In the diagrams, all light bulbs are identical, all cells are ideal and identical. In which circuit will the bulbs be dimmest?

1. 

2. 

3. 

4. 

A battery or batteries, connected to two parallel plates produce equipotential lines between the plates as shown. Which of the following configurations is most likely to produce these equipotential lines?

1. 

2.

3. 

4. 

In the circuit diagram, all the bulbs are identical. Which bulb will glow the brightest?

1. A

2. B

3. C

4. D

A cuboid has the longest dimension double the shortest dimension. Then the ratio of maximum to minimum resistance across its parallel faces is :

1. 2: 1

2. 4: 1

3. 8: 1

4. 3: 2 

A current passes through a wire of non-uniform cross-section. Which of the following quantities is independent of the cross-section?

1. the charge crossing in a given time interval

2. drift speed

3. current density

4. electric field

Two identical fuses are rated at 10 A. If they are joined:

1. in parallel, the combination acts as a fuse of rating 20 A.

2. in parallel, the combination acts as a fuse of rating 5 A.

3. in series, the combination acts as a fuse of rating 100 A.

4. in series, the combination acts as a fuse of rating 20 A.

The ammeter connected in the following circuits has zero resistance. The voltmeter in option 1 has infinite resistance and a reading of 8 V. The value of resistance R has not been specified. Which of the remaining circuits has the same current in the ammeter as option 1?

1. 

2. 

3. 

4.