(English Medium) ICSE Class 10 - CISCE Question Bank Solutions

The transformer is used in ______ current circuits.

In a transformer, the frequency of A.C. voltage ______. 

What is the function of a transformer in an a.c. circuit? How do the input and output powers in a transformer compare?

Name two kind of energy loss in a transformer. How is it minimized?

The primary coil of a transformed has 800 urns and the secondary coil has 8 turns. It is connected to a 220 V a.c. supply. What will be the output voltage?

A transformer is designed to work from a 240 V a.c. mains and to give a supply of 8 V to ring a house bell. The primary coil has 4800 turns. How many turns will be in the secondary coil?

The input and output voltage of a transformer are 220 V and 44 V respectively. Find:  the turns ratio.

The diagram above shows a circuit with the key k open. Calculate :
(i) the resistance of the circuit when the key k is open.
(ii) the current drawn from the cell when the key k is open.
(iii) the resistance of the circuit when the key k is closed.
(iv) the current drawn from the cell when the key k is closed.

The diagram below shows a magnetic kept just below the conductor AB which is kept in North South direction.

(i) In which direction will the needle deflect when the key is closed ?
(ii) Why is the deflection produced ?
(iii) What will be the change in the deflection if the magnetic needle is taken just above the conductor AB ?
(iv) Name one device which works on this principle.

What is wrong with the circuit diagram (Fig. 34)? Carefully check the symbols and assign proper positive and negative signs to them.

A simple electric circuit has 24 V battery and a resistor of 60 Ω. What will be the current in the circuit? The resistance of the connecting wires is negligible.

What is the current I in the given circuit (Fig. )?

A simple electric circuit has a 30 V battery and a resistor ot 60 o. What will be the current in the circuit? The resistance of the oonnecting wires is negligible.