NEET
- Exam
- NEET
- Subject
- Physics
- Chapter
- Electromagnetic Induction
NEET · Physics · Electromagnetic Induction
Given below are two statements: one is labelled as Assertion (A)...
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : When a coil is rotated in a uniform magnetic field about an diametrical axis perpendicular to the field, emf is induced in it which is maximum for the orientation of coil in which magnetic flux through the coil is zero.
Reason (R) : In an electric generator, electrical energy is generated by rotating a coil in a magnetic field.
In the light of the above statements, choose the most appropriate answer from the options given below:
Options
- ABoth (A) and (R) are true and (R) is the correct explanation of (A).
- BBoth (A) and (R) are true and (R) is NOT the correct explanation of (A).
- C(A) is true but (R) is false.
- D(A) is false but (R) is true.
Correct answer
B. Both (A) and (R) are true and (R) is NOT the correct explanation of (A).
Step-by-step solution
- Assertion (A) is True: The induced EMF in a rotating coil is proportional to the rate of change of magnetic flux. When the magnetic flux through the coil is zero, its rate of change is maximum, leading to a maximum induced EMF.
- Reason (R) is True: An electric generator indeed works on the principle of rotating a coil in a magnetic field to produce electrical energy.
- Reason (R) is NOT the correct explanation for Assertion (A): While both statements are true, Reason (R) describes the general function of a generator, but it doesn't explain why the EMF is maximum when the flux is zero. That explanation comes from the mathematical relationship between flux (cosine function) and induced EMF (sine function, which is maximum when cosine is zero).
Therefore, both statements are true, but the reason does not explain the assertion.
The correct option is (2).