The magnitude of force acting on a current carrying wire placed in a magnetic field in a direction perpendicular to its length depends on :

1. The current flowing in the wire
2. The strength of the magnetic field
3. The length of the wire
4. all of the above

The speed of rotation of coil can be increased by :

1. decreasing the strength of the magnetic field
2. decreasing the area of the coil
3. increasing the area of the coil
4. decreasing the number of turns in the coil

Four wires each of length 2 m are bent in the form of four loops P, Q, R and S as shown below. They are suspended in a uniform magnetic field. Each loop carries the same current. Identify the correct statement.

1. torque on loop P is maximum.
2. torque on loop Q is maximum.
3. torque on loop R is maximum.
4. torque on loop S is maximum.

How will the direction of force be changed, if the current is reversed in the conductor placed in a magnetic field?