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
(1) R1/R2
(2) R2/R1
(3)
(4)
Consider the situation shown in the figure. The wire AB is sliding on the fixed rails with a constant velocity. If the wire AB is replaced by semicircular wire, the magnitude of the induced current will:
1. | increase. |
2. | remain the same. |
3. | decrease. |
4. | increase or decrease depending on whether the semicircle bulges towards the resistance or away from it. |
A circular loop of radius R carrying current i lies in the x-y plane. If the centre of the loop coincides with the origin, then the total magnetic flux passing through the x-y plane will be:
1. | directly proportional to I. |
2. | directly proportional to R. |
3. | directly proportional to R2. |
4. | Zero. |
A small square loop of wire of side l is placed inside a large square loop of wire of side L (L > l). The loop are coplanar and their centre coincide. The mutual inductance of the system is proportional to
(1) l / L
(2) l2 / L
(3) L/l
(4) L2/l
A uniform but time-varying magnetic field B(t) exists in a circular region of radius a and is directed into the plane of the paper, as shown. The magnitude of the induced electric field at point P at a distance r from the centre of the circular region:
1. is zero
2. decreases as
3. increases as r
4. decreases as
Two circular coils can be arranged in any of the three situations shown in the figure. Their mutual inductance will be:
1. | maximum in the situation (A). |
2. | maximum in the situation (B). |
3. | maximum in the situation (C). |
4. | the same in all situations. |
A conducting rod of length 2l is rotating with constant angular speed about its perpendicular bisector. A uniform magnetic field exists parallel to the axis of rotation. The e.m.f. induced between the two ends of the rod is:
1. \(B\omega l^2\)
2.
3.
4. Zero
As shown in the figure, P and Q are two coaxial conducting loops separated by some distance. When the switch S is closed, a clockwise current IP flows in P (as seen by E) and an induced current flows in Q. The switch remains closed for a long time. When S is opened, a current flows in Q. Then the directions of and (as seen by E) are
(1) Respectively clockwise and anticlockwise
(2) Both clockwise
(3) Both anticlockwise
(4) Respectively anticlockwise and clockwise
A conducting wireframe is placed in a magnetic field that is directed into the paper. The magnetic field is increasing at a constant rate. The directions of induced current in wires AB and CD are
(1) B to A and D to C
(2) A to B and C to D
(3) A to B and D to C
(4) B to A and C to D
A conductor ABOCD moves along its bisector with a velocity of 1 m/s through a perpendicular magnetic field of \(1~\mathrm{wb/m^2}\), as shown in fig. If all the four sides are of 1 m length each, then the induced emf between points A and D is:
1. 0
2. 1.41 volt
3. 0.71 volt
4. None of the above