(a) At right angles to the axis of magnetic field.
(b) Along the axis of the magnetic field.
(c) At 45° angles to the axis of magnetic field.
(d) Anywhere.
Answer: (a) Right angles to the axis of magnetic
field
Explanation:
CONCEPT: Induced Voltage in a Rotating Conductor
- When
a conductor moves in a magnetic field, an EMF
(voltage) is induced in it.
- The
magnitude of the induced voltage depends on how effectively the
conductor cuts magnetic flux lines.
- This
effectiveness is determined by the angle between the conductor’s
velocity and the magnetic field.
Formula for Induced Voltage
- The
induced voltage in a conductor is given by:
Where:
= induced voltage
= magnetic flux
density
= effective
length of conductor
= velocity of the
conductor
= angle between
velocity vector and magnetic field
Explanation
- The
induced voltage is proportional to
. - The
value of is maximum
(equal to 1) when:
- At
this position:
- The
conductor moves perpendicular to the magnetic field lines.
- It
cuts the maximum number of flux lines per second.
- Hence,
the rate of change of flux linkage is maximum.
- Therefore,
the induced voltage reaches its peak value.
Final Answer
✅ Correct option: (a)
Right angles to the axis of magnetic field
✔️ Key One-Line Exam Statement
Peak induced voltage occurs when the conductor moves
perpendicular to the magnetic field.
Important Exam Notes
→ induced voltage
= 0- → induced voltage
= maximum
- Voltage
depends on sin θ, not cos θ