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

(i) Draw a clear labelled diagram of an electric bell.
(ii) Explain in brief, its working.
(iii) What material is used for the core of an electric bell? State the reason.

Copy the given diagram of a transformer and complete it. Name the parts A and B. Name the part you have drawn to complete the diagram. What is the material of this part? Is this transformer a step-up or step-down? Give reason.

The power supply to the primary coil of a transformer is 200 W. Find
(i) Current in primary coil if the e.m.f. supply to it is equal to 220V.
(ii) The number of turns in the primary coil is equal to 80 and that in secondary is 800. What is the transformation ratio?
(iii) Name the type of transformer.
(iv) What will be the output voltage?
(v) What is the current in the secondary coil for an ideal transformer?
(vi) What is the output power?
(vii) Is output and input power equal?
(viii) Compare the current flowing in a secondary coil and in a primary coil.

The primary coil of a transformer has 200 turns while the secondary coil has 1000 turns. What type of transformer is this? if the input voltage is 10V, what will be the output voltage?

Applying e.m. f to primary coil is 210 V. If the number of turns in primary coil is 200 turns and that of in secondary coil is 20 turns, then find out the output voltage. Name the type of transformer.

A transformer lowers e.m.f. 220 V to 12 volts. If the number of turns in primary are 8800, how many turns are in secondary coil?

A transformer lowers e.m.f. from 220 V to 15 V. If 400 W power is given in primary, calculate (i) the current in primary coil and (ii) the current in secondary coil.

A transformer lowers e.m.f. from 220 V to 15 V. If the number of turns in primary are 3520, how many turns are in the secondary coil?

Name one electrical device which works on Faraday's law of electromagnetic induction principle.

A fuse is rated 5 A. Can it be used with a geyser rated 1540 W, 220 V Write Yes or No. Give supporting calculations to justify your answer.

Water freezes to form ice. What change would you expect in the average kinetic energy of the molecules?

1 kWh = ______ J.

For what purpose are the transformers used?

How do the input and output powers in a transformer compare? State the assumption made.

Define the term kilowatt-hour and state its value in S.I unit

The temperature of the surrounding starts falling when ice in a frozen lake starts melting. Give reason.

What do you mean by power rating of an electrical appliance? How do you use it to calculate the resistance of the appliance.

What do you mean by power rating of an electrical appliance? How do you use it to calculate the safe limit of current in it, while in use?

An electrical appliance has a rating 100 W, 120 V. The resistance of element of appliance when in use is ______.

State one advantage of using a total reflecting prism as a reflector in place of plane mirror.