Magnetic Field due to a Current Carrying Conductor

Q.

What is a split-ring commutator in a dc motor? Explain the function of the same.

Q. A current carrying conductor is placed in an uniform magnetic field. The direction of current is parallel to the direction of magnetic field. The magnetic force $F$ acting on the conductor is_______. ( Length of the conductor $L$, current $I$).

1. zero
2. $\text{F}=\text{ILB}$
3. $\text{F}=\text{IL}{\text{B}}^2$
4. $\text{F}$ = $\text{ILB/2}$

Q.

When the coils of an electric generator rotate in a magnetic field,

1. the mechanical energy changes into electric energy.

2. the thermal energy changes into electric energy.

3. the solar energy changes into electric energy.

4. the wind energy changes into electric energy.

Q.

In the figure given below iron filings are sprinkled on a cardboard perpendicular to which a current carrying copper wire runs. The other components of the circuit have their usual meanings

If the polarity of the battery in the circuit is changed then

1. Nothing happens to the compass

2. The deflection of the compass needle gets reversed

3. The deflection of the compass needle increases a little

4. The deflection of the compass needle decreases a little

Q. The magnetic field generated by a current carrying conductor is dependent on the of the current flowing.

1. magnitude, direction
2. work, displacement
3. force, torque

Q.

Flemings right hand rule gives

1. the magnitude of the induced emf.

2. the magnitude of the magnetic field.

3. the direction of the induced emf

4. both magnitude and direction of the induced emf.

Q.

What happens when a soft iron bar is instated in current carrying solenoid?

Q. When there is a moving magnet in the vicinity of a coil, there will be current flowing through the coil.

1. True
2. False

Q. The magnetic field lines generated due to current flowing through a circular coil resembles that of a dipolar magnet.

1. False
2. True

Q.

The magnetic field lines inside a current carrying solenoid are _____________.

1. parallel to each other

2. perpendicular to each other

3. inclined at angle with respect to the solenoid
4. None of the above

Q. Match the following direction entities according to the Fleming's right hand rule.

1. Induced current
2. Motion
3. Magnetic field

Q. If current is made to flow in the clockwise direction through a circular coil; a magnetic south pole is generated.

1. True
2. False

Q. If current is made to flow in the anti-clockwise direction through a circular coil; a magnetic north pole is generated.

1. False
2. True

Q. A freely suspended current carrying solenoid aligns itself in the north-south direction.

1. True
2. False

Q. Hans Oersted was the scientist who discovered the magnetic effects of a current carrying conductor.

1. True
2. False

Q. The strength of the magnetic field generated by a current carrying wire is directly proportional to the magnitude of current flowing.

1. False
2. True

Q. Which part of the current carrying circular loop represents the strongest magnetic field?

1. A point outside the loop.
2. A point on the circumference of the loop.
3. Centre of the loop.
4. A point close to the centre of the loop.

Q.

Which of the following correctly describes the magnetic field lines near a long straight wire?

1. The field consists of straight lines perpendicular to the wire

2. The field consists of straight lines parallel to the wire

3. The field consists of radial lines originating from the wire

4. The field consists of concentric circles centred on the wire