Household Electrification

Q.

A bulb is rated 5 V and 500 mA. Calculate its (a) power, (b) resistance, and (c) energy consumed when it is lighted for 4 hours.

Q. 1. (a) What is the function of
(i) live wire
(ii) ​​neutral wire
(iii) earth wire
(b) what is overloading and short circuiting.

Q.

Household appliances are connected in _______.

1. Series

2. Parallel

3. They are not connected at all

4. One by one

Q.

An electric kettle is rated at 230 V, 1000 W. What is the resistance of its element?

1. 63.5 Ώ

2. 52.9 Ώ

3. 59.2 Ώ

4. 65.3 Ώ

Q. Full form of E.L.C.B is:

1. Earth leakage circuit breaker
2. Electric leakage current breaker
3. Earth leakage current breaker
4. Electric leakage circuit breaker

Q. How does fuse wire protects electrical appliances?

Q.

Explain:
a) Electric fuse
b) Overloading
c) Short circuit [3 MARKS]

Q. The electrical appliances in a house are usually connected in:

1. series
2. parallel
3. (a) and (b) above.
4. star circuit

Q.

A geyser has a rating of 2 kW, 240 V. What is the cost of using it for 30 minutes if the cost of electricity is Rs. 3 per commercial units?

1. Rs. 2

2. Rs. 4

3. Rs. 5

4. Rs. 3

Q.

The safety device based on the heating effect of electric current is called a ______.

Q.

Why household wiring is done in parallel wiring system?

1. All appliances may get an appropriate voltage of 230 Volt each

2. If one appliance blows out, others may work

3. All appliances may be switched on and off separately.

4. All of these

Q.

The __ is a safety device used in case of overloading and short-circuits.

Q. Calculate the electricity bill for $30days$ if an air conditioner of rating $2kW$ is operated for $4hours$ per day. The cost of electricity per unit is $Rs.5$.

1. $Rs.120$
2. $Rs.200$
3. $Rs.2000$
4. $Rs.1200$

Q.

An electric bulb is marked $100\mathrm{W},250\mathrm{V}$. How much current will the bulb draw, if connected to a $250\mathrm{V}$ supply?

Q.

An electric bulb is rated 500W - 200V. Calculate the magnitude of the current.

1. 100 A

2. 0.4 A

3. 2.5 A

4. 10 A

Q.

How is a fuse put in an electric circuit? State the purpose of using a fuse in a circuit.

Q.

The most important safety method used for protecting home appliances from short circuiting or overloading is

1. Use of stabilizers

2. Earthing

3. Use of fuse

4. Use of electric meter

Q. All household wiring are done in series wiring system.

1. True
2. False

Q.

Which of the following is/are the characteristics of a fuse wire?

1. Low melting point

2. High melting point

3. High conductivity

4. Low conductivity

Q. Fuse wire is made up of an alloy of ................ which has high resistance and ............. (High/Low) melting point.

Q.

SI unit of ‘rate of doing work’ is

1. J

2. W

3. kW

4. kWh

Q. Consider the same Carnot engine that operates between the temperatures $T_H$ 850 K and $T_L$300 K. The engine performs 1200 J of work each cycle, which takes 0.25 s. What is the average power of this engine?

1. 4.8 kw

2. 4.8 w

3. 5.6 kw

4. 5.6 w

Q.

An electric bulb is rated $220V$ and $100W$. Power consumed by it operated on $110V$ is

Q. Full form of M.C.B is:

1. Miniature circuit breaker
2. Minimum current breaker
3. Miniature current breaker
4. Minimum circuit breaker

Q.

Name a safety device which is used to limit the current in an electrical circuit. The use of this device safeguards the circuit and the appliances connected in that circuit from being damaged.

1. Fuse Wire

2. Earthing Wire

3. Switch

4. Neutral Wire

Q.

Fuse wire is made of an alloy of :

1. iron and tin

2. copper and lead

3. tin and lead

4. copper and iron

Q. An electric meter reads 8950 KWh at the end of the month, while at the beginning of the month the reading was 8833 KWh. How many units of electricity .are consumed ? If one unit costs Rs. 4.30, find the cost of the electrical energy consumed.

Q. Assertion :Kilowatt hour is the unit of electric power. Reason: Watt hour has units of energy.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is incorrect but Reason is correct
4. Both Assertion and Reason are incorrect

Q.

A geyser has a label $2kW,240V$. What is the cost of running it for $30minutes,$if the cost of electricity is $rupees3$ per unit?

Q.

Power voltage rating of an electric bulb is 100 W 200 V, current drawn by it will be