Will there be any change in the ammeter reading if the length of the wire in the circuit is doubled? Explain your answer.

Suresh arranges the electric circuit shown below to measure the current flowing through and the potential difference of a bulb.

Is the circuit correct? If not, then identify the mistake.

Study the circuit diagram given below. You are given one extra resistor. By drawing a new circuit diagram, show how you can connect the extra resistor to increase the reading on the ammeter in the circuit below.

Observe the circuit shown below. All the three switches are open.

Identify the switch/switches that on being closed will cause the fuse to blow.

The following four circuits have been made for studying the dependence of current on the potential difference across a resistor.

The correct circuit is:

The resultant resistance of the circuit between A and B is

The potential difference across $4 \mathrm{\Omega }$ will be