In a step up transformer:

1. N_s = N_p
2. N_s < N_p
3. N_s > N_p
4. nothing can be said

A step up transformer …………… the current whereas a step down transformer …………… the current.

1. increases, increases
2. decreases, decreases
3. decreases, increases
4. increases, decreases

A bar magnet is kept along the axis of a circular coil as shown in the figure given below. The magnet is rotated (i) about its own axis and (ii) about an axis perpendicular to the length of the magnet. The induced emf is generated at the terminals of the coil in :

1. (i) only
2. (ii) only
3. none of the cases
4. both the cases

(i) The number of turns in the secondary coil of a transformer is 20 times than that in a primary coil. If the power fed to the primary coil is 100 W (assume no energy loss), then what is the power output at the secondary coil ?

1. 5 W
2. 100 W
3. 2000 W
4. 4000 W

(ii) If the primary coil of the above transformer is supplied with 10 V, what is the voltage of the secondary coil ?

1. 0.5 V
2. 10 V
3. 200 V
4. 100 V