Science for Tenth Class Part - 1 Physics>Chapter 1 - Electricity>Short Answer Type Questions>Q 26

EASY

10th CBSE

IMPORTANT

Earn 100

A $2 kW$ heater, a $200 W$ TV and three $100 W$ lamps are all switched on from $6 pm to 10 pm$ . What is the total cost at $₨ 5.50$ per $kWh$ ?

Important Questions on Electricity

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IMPORTANT

Science for Tenth Class Part - 1 Physics>Chapter 1 - Electricity>Short Answer Type Questions>Q 27

What is the maximum power in

kilowatts

of the appliance that can be connected safely to a $13 A, 230 V$ mains socket?

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10th CBSE

IMPORTANT

Science for Tenth Class Part - 1 Physics>Chapter 1 - Electricity>Short Answer Type Questions>Q 28

An electric fan runs from the $230 V$ mains. The current flowing through it is $0.4 A$ . At what rate is electrical energy transferred by the fan?

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Science for Tenth Class Part - 1 Physics>Chapter 1 - Electricity>Long Answer Type Questions>Q 29

(a) What is meant by "electric power"? Write the formula for electric power in terms of potential difference and current.
(b) The diagram below shows a circuit containing a lamp

L

, a voltmeter and an ammeter. The voltmeter reading is $3 V$ , and the ammeter reading is

0.5 A

.

(i) What is the resistance of the lamp?
(ii) What is the power of the lamp?
(c) Define

kilowatt - hour

. How many

joules

are there in one

kilowatt - hour

?
(d) Calculate the cost of operating a heater of $500 W$ for

20 hours

at the rate of

₹ 3.90 p e r unit

.

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10th CBSE

IMPORTANT

Science for Tenth Class Part - 1 Physics>Chapter 1 - Electricity>Multiple Choice Questions (MCQs)>Q 30

When an electric lamp is connected to

12 V

battery, it draws a Current Of $0.5 A$ . The power of the lamp is:

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IMPORTANT

Science for Tenth Class Part - 1 Physics>Chapter 1 - Electricity>Multiple Choice Questions (MCQs)>Q 31

The unit for expressing electric power is:

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Science for Tenth Class Part - 1 Physics>Chapter 1 - Electricity>Multiple Choice Questions (MCQs)>Q 32

Which of the following is likely to be the correct wattage for an electric iron used in our homes?

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10th CBSE

IMPORTANT

Science for Tenth Class Part - 1 Physics>Chapter 1 - Electricity>Multiple Choice Questions (MCQs)>Q 33

An electric heater is rated at $2 kW$ . Electrical energy costs

₹ 4 p e r kWh

. What is the cost of using the heater for

3 hours

?

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10th CBSE

IMPORTANT

Science for Tenth Class Part - 1 Physics>Chapter 1 - Electricity>Multiple Choice Questions (MCQs)>Q 34

The SI unit of energy is: