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Question
The mutual inductance M12 of coil 1 with respect to coil 2 ______.
- increases when they are brought nearer.
- depends on the current passing through the coils.
- increases when one of them is rotated about an axis.
- is the same as M21 of coil 2 with respect to coil 1.
Options
a and b
b and c
c and d
a and d
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Solution
a and d
Explanation:
Mutual Induction: Whenever the current passing through a coil or circuit changes, the magnetic flux linked with a neighbouring coil or circuit will also change. Hence an emf will be induced in the neighbouring coil or circuit. This phenomenon is called ‘mutual induction’.
The mutual inductance M12 of coil 1 w.r.t. coil 2 increases when they are brought nearer and is the same as M21 of coil 2 with respect to coil 1.
M12, i.e., mutual inductance of solenoid S1 with respect to solenoid S2 is given by
`M_12 = (mu_0N_1N_2pir_1^2)/l`
Where signs are as usual.
Also, M21, i.e., mutual inductance of solenoid S2 with respect to solenoid S1 is given by
`M_21 = (mu_0N_1N_2pir_1^2)/l`
So, we have M12 = M21 = M
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