As shown in the figure, a magnet is moved with a fast speed towards a coil at rest. Due to this induced electromotive force, induced current and induced charge in the coil is E, I, and Q respectively. If the speed of the magnet is doubled, the incorrect statement is
1. E increases
2. I increases
3. Q remains the same
4. Q increases
A coil having 500 square loops each of the side 10 cm is placed normal to a magnetic field which increases at the rate of 1.0 tesla/second. The induced e.m.f. in volts is
1. 0.1
2. 0.5
3. 1
4. 5
When a magnet is pushed in and out of a circular coil C connected to a very sensitive galvanometer G as shown in the adjoining diagram with a frequency v, then
1. Constant deflection is observed in the galvanometer
2. Visible small oscillations will be observed in the galvanometer if v is about 50 Hz
3. Oscillations in the deflection will be observed clearly if v = 1 or 2 Hz
4. No variation in the deflection will be seen if v = 1 or 2 Hz
The magnetic field in a coil of 100 turns and 40 square cm area is increased from 1 Tesla to 6 Tesla in 2 second. The magnetic field is perpendicular to the coil. The e.m.f. generated in it is
1. 104 V
2. 1.2 V
3. 1.0 V
4. 10–2 V
A metallic ring connected to a rod oscillates freely like a pendulum. If now a magnetic field is applied in the horizontal direction so that the pendulum now swings through the field, the pendulum will
1. Keep oscillating with the old-time period
2. Keep oscillating with a smaller time period
3. Keep oscillating with a larger time period
4. Come to rest very soon
In a circuit with a coil of resistance \(2~\Omega,\) the magnetic flux changes from \(2.0\) Wb to \(10.0\) Wb in \(0.2\) s. The charge that flows in the coil during this time is:
1. \(5~\text{C}\)
2. \(4~\text{C}\)
3. \(1~\text{C}\)
4. \(0.8~\text{C}\)
The total charge induced in a conducting loop when it is moved in the magnetic field depends on
1. The rate of change of magnetic flux
2. Initial magnetic flux only
3. The total change in magnetic flux
4. Final magnetic flux only
An aluminum ring B faces an electromagnet A. The current I through A can be altered. Then :
1. Whether I increases or decreases, B will not experience any force
2. If I decrease, A will repel B
3. If I increases, A will attract B
4. If I increases, A will repel B
A coil having \(n\) turns and resistance \(R~\Omega\) is connected with a galvanometer of resistance \(4R~\Omega\). This combination is moved in time \(t\) seconds from a magnetic field \(W_1\) weber/m2 to \(W_2\) weber/m2. The induced current in the circuit is:
(Assume area = \(1\) m2)
1. | \(-\dfrac{(W_2-W_1)}{5Rnt}\) | 2. | \(-\dfrac{n(W_2-W_1)}{5Rt}\) |
3. | \(-\dfrac{(W_2-W_1)}{Rnt}\) | 4. | \(-\dfrac{n(W_2-W_1)}{Rt}\) |
A rectangular coil ABCD is rotated anticlockwise with a uniform angular velocity about the axis shown in the diagram below. The axis of rotation of the coil as well as the magnetic field B are horizontal. The induced e.m.f. in the coil would be maximum when
1. The plane of the coil is horizontal
2. The plane of the coil makes an angle of 45° with the magnetic field
3. The plane of the coil is at right angles to the magnetic field
4. The plane of the coil makes an angle of 30° with the magnetic field