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

Why is the core of a transformer laminated?

Define watt-hour. How many joules are equal to 1 watt-hour?

Define kilowatt-hour. 

The frequencies of notes given by flute, guitar and trumpet are respectively 400 Hz, 200 Hz and 500 Hz. Which one of these has the highest pitch?

Write an expression for the electrical power spent in flow of current through a conductor in terms of
(a) Resistance and potential difference, (b) current and resistance.

Electrical power P is given by the expression P = (Q × V) ÷ time. What do the symbols Q and V represent?

Electrical power p is given by the expression P = (Q × V) ÷ time. Express the power P in terms of current and resistance explaining the meaning of symbols used there in.

Name the S.I. unit of electrical energy. How is it related to Wh?

Name the S.I unit of electrical energy. How is it related to Wh?

State the S.I. unit of electrical power.

 State and define the household unit of electricity.

Name the physical quality which is measured in
(i) Kw (ii) kWh

Distinguish between kilowatt and kilowatt-hour.

 1Kwh =`( 1  "volt "xx 1 am pere xx.............)/1000`

1kWh = …….. J

An electric bulb is rated ‘100 W, 250 V’. What information does this convey?

List the names of three electrical gadgets used in your house. Write their power, voltage ratingand approximate time for which each one is used in a day. Hence find the electrical energyconsumed by each in a day.

Two lamps, one rated 220 V, 50 W and the other rated 220 V, 100 W, are connected in serieswith mains of 220 V. Explain why does the 50 W lamp consume more power

When a current I flows through a resistance R for time t, the electrical energy spent is given by:
(a) IRt (b) I²Rt (c) `IR^2t` (d) `I^2R ⁄t`

A current of 2 A is passed through a coil of resistance 75Ω for 2 minutes. (a) How much heat energy is produced? (b) How much charge is passed through the resistance?