Vidaara.orgClass 10 · Physics
CodeVID-P10-04-FCM-01
Force on a Conductor & Electric Motor — Assignment
Name: ____________________
Roll No.: __________
Date: ____________
General Instructions
- All questions are compulsory.
- Section A carries 1 mark each, Section B 2 marks, Section C 3 marks and Section D 5 marks.
- Draw neat labelled diagrams wherever asked. For full solutions, raise your doubts with your teacher.
Section A — Multiple Choice Questions
5 × 1 = 5 marks
1.
Force on a conductor is maximum when current is ___ to the field.
- A.parallel
- B.perpendicular
- C.at 45°
- D.zero
2.
Fleming's left-hand rule gives the direction of:
- A.field
- B.force
- C.charge
- D.resistance
3.
A motor converts electrical energy into:
- A.heat
- B.mechanical energy
- C.light
- D.sound
4.
The commutator in a motor is a:
- A.full ring
- B.split ring
- C.fuse
- D.switch only
5.
The middle finger in Fleming's left-hand rule shows:
- A.field
- B.force
- C.current
- D.power
Section B — Short Answer (2 marks)
3 × 2 = 6 marks
6.
State Fleming's Left-Hand Rule.
7.
When is the force on a current-carrying conductor zero?
8.
Name the energy conversion in an electric motor.
Section C — Short Answer (3 marks)
2 × 3 = 6 marks
9.
Explain why the coil of a motor rotates continuously.
10.
List three factors on which the force on a conductor depends.
Section D — Long Answer (5 marks)
1 × 5 = 5 marks
11.
Describe the construction and working of a simple electric motor with a labelled diagram, explaining the role of the split-ring commutator.
Answer Key
Section A — Multiple Choice Questions
- (B) perpendicular
- (B) force
- (B) mechanical energy
- (B) split ring
- (C) current
Section B — Short Answer (2 marks)
- Forefinger = field, middle finger = current, thumb = force/motion.
- When the conductor is parallel to the magnetic field.
- Electrical energy to mechanical energy.
Section C — Short Answer (3 marks)
- Opposite forces on the two arms form a couple; commutator reverses current each half turn.
- Strength of current, strength of field, and angle between them.
Section D — Long Answer (5 marks)
- Coil between magnet poles; Fleming's rule gives opposite forces; commutator reverses current each half turn for continuous rotation.
Generated by Vidaara.org · Assignment VID-P10-04-FCM-01 · vidaara.org