Advertisements
Advertisements
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
Advertisements
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
APPEARS IN
RELATED QUESTIONS
The co-efficient of mutual induction between primary and secondary coil is 2H. Calculate induced e.m.f. if current of 4A is cut off in 2.5 x 10-4 seconds
Draw a necessary arrangement for winding of primary and secondary coils in a step-up transformer. State its underlying principle and derive the relation between the primary and secondary voltages in terms of number of primary and secondary turns. Mention the two basic assumptions used in obtaining the above relation.
Define mutual inductance.
A long solenoid with 15 turns per cm has a small loop of area 2.0 cm2 placed inside the solenoid normal to its axis. If the current carried by the solenoid changes steadily from 2.0 A to 4.0 A in 0.1 s, what is the induced emf in the loop while the current is changing?
A pair of adjacent coils has a mutual inductance of 1.5 H. If the current in one coil changes from 0 to 20 A in 0.5 s, what is the change of flux linkage with the other coil?
A coil of self-inductance 2.5H and resistance 20Ω is connected to a battery of emf 120V having the internal resistance of 5 n. Find:
1) The time constant of the circuit.
2) The current in the circuit in steady state
Find the mutual inductance between the straight wire and the square loop of figure.

The mutual inductance of two coils is 10 mH. If the current in one of the coil changes from 5 A to 1 A in 0.2 s, calculate the emf induced in the other coil. Also calculate the induced charge flowing through the coil if its resistance is 5 Ω.
Two coils P and Q are kept near each other. When no current flows through coil P and current increases in coil Q at the rate 10 A/s, the e.m.f. in coil P is 20 mV. When coil Q carries no current and current of 1.6 A flows through coil P, the magnetic flux linked with the coil Q is ____________.
A current I = 10 sin (50 π t) ampere is passed in the first coil which induces a maximum e.m.f. of 5 π volt in the second coil. The mutual inductance between the coils is ______.
A coil of radius 'r' is placed on another coil (whose radius is 'R' and current flowing through it is changing) so that their centres coincide. (R>>r) if both the coils are coplanar then the mutual inductance between them is proportional to ______.
Alternating current of peak value `(2/pi)` ampere flows through the primary coil of transformer. The coefficient of mutual inductance between primary and secondary coil is 1 H. The peak e.m.f. induced in secondary coil is ______. (Frequency of a.c. = 50 Hz)
Two coils P and Q have mutual inductance 'M' H. If the current in the primary is I = I0 sin `omega`t, then the maximum vlaue of e.m.f. indued in coil Q is ____________.
The mutual inductance between two coils is 0.09 henry. If the current in the primary coil changes from 0 to 20 A in 0.006 s, the e.m.f. induced in the secondary coil at that instant is ____________.
Two circular coils have their centres at the same point. The mutual inductance between them will be maximum when their axes ______
Two conducting circular loops of radii R1 and R2 are placed in the same plane with their centres coinciding. If R1 > > R2, the mutual inductance M between them will be directly proportional to ______.
Two circular loops, one of small radius r and the other of larger radius R, such that R >> r, are placed coaxially with centres coinciding. Obtain the mutual inductance of the arrangement.
Two planar concentric rings of metal wire having radii r and r2 (r₁ > r2) are placed in air. The current I is flowing through the coil of larger radius. The mutual inductance between the coils is given by ( μο = permeability of free space) ______.
