Domestic Circuits

Q.

A fuse wire should have

1. High resistance

2. Low melting point

3. Both (1) and (2)

4. None of above.

Q.

What Is Kit Kat Fuse?

Q.

Find the energy in $kWh$ consumed in $10$ hours by four devices of power $500W$ each.

Q.

One kilowatt hour is defined as?

Q.

What is the full form of RCD?

Q.

What is the function of a safety device?

1. To complete the circuit, so that high current flows through the circuit.

2. To break the circuit when a high current flows through the circuit.

3. To break the circuit as soon as current flows through the circuit.

4. To allow small amount of current to pass through the circuit.

Q. An electric fuse is always connected in parallel in an electric circuit.

1. False
2. True

Q.

Electric fuse works on the principle of _________ effect of electric current.

1. chemical

2. luminous

3. heating

4. magnetic

Q. An electric kettle works on the principle of heating effects of electric current.

1. False
2. True

Q. Which of the following electrical appliances does not have a heating element?

1. Electric toaster
2. Electric cooker
3. Soldering iron
4. Electric switch

Q.

The correct relation between heat produced, $H$ and electric current, $I$ flowing is

1. H directly proportional to (1/I)

2. H directly proportional to I

3. H directly proportional to I²

4. H directly proportional to (1/I²).

Q.

An electric bulb is rated $220V$ and $100W.$ When it is operated at $110V,$ the power consumed will be

1. $75\text{W}$
2. $25\text{W}$
3. $50\text{W}$
4. $100\text{W}$

Q. How much is the heat energy produced in $10seconds$ in an electric iron having resistance $440\Omega$, when a potential difference of $220volt$ is applied across it?

1. $1500J$
2. $1100J$
3. $600J$
4. $300J$

Q.

Which of the following represents electrical power in a circuit?

1. I²R

2. IR²

3. VI

4. V²/R

Q.

A fan of power $550W$ works for $3hours$. Calculate the energy consumed.

1. $2kWh$

2. $1.5kWh$

3. $1.65kWh$

4. $2.5kWh$

Q.

An electric device of 50 W is made to run for $20h$ per day. If one unit costs $₹2.50$, then the electric bill for the month of November is $₹$

1. $125$

2. $150$

3. $75$

4. $50$

Q. Voltage drop across the conductor is having resistance $100\Omega$ and current flowing through it is $5A$.

1. 50 V
2. 5 V
3. 0.5 V
4. 500 V

Q. Given are the melting point of three materials, which material do you think will be suitable for being used as connecting wire, fuse and filament respectively?
Material I: ${400}^{\circ }C$
Material II: ${1200}^{\circ }C$
Material III: ${3400}^{\circ }C$

1. Material I – Connecting Wire
   Material II – Fuse
   Material III - Filament
2. Material I –Filament
   Material II – Fuse
   Material III –Connecting Wire
3. Material I - Filament
   Material II - Connecting Wire
   Material III - Fuse
4. Material I –Fuse
   Material II – Connecting Wire
   Material III - Filament

Q.

Name the commercial unit of electric energy.

Q.

The resistance of a bulb fitted in a house varies inversely as its

1. power

2. potential drop

3. current

4. none of these

Q.

In a house, three tube lights each of$40W$, two electric bulbs each of $100W$ and a fridge of $500W$ runs six hours daily. What is the consumption of electric units in a house in a month? Calculate also the cost of electricity consumed in a month if the cost of electricity for a unit is $Rs2$.

Q.

A bulb of $40W$ is designed to operate at $240V$. What is the resistance of the filament of the bulb.

1. $9600\Omega$

2. $60\Omega$

3. $1400\Omega$

4. $1440\Omega$

Q.

In what unit does the domestic electric meter measure the electric energy consumed. State the value of this unit in SI unit.

Q.

In what unit does the domestic electric meter measure the electrical energy consumed? State the value of unit in $S.I$ unit.

Q. A 220 V, 100 W bulb is connected to a 110 V source. Calculate the power consumed by the bulb.

1. 15 W
2. 20 W
3. 25 W
4. 10 W

Q.

The current in a circuit is doubled, keeping other parameters constant. The heat generated in the circuit will be _________ of its initial value.

1. $2times$

2. $4times$

3. $3times$

4. $8times$

Q. If a wire of resistance $20\Omega$ is covered with ice and a voltage of 210 V is applied across the wire, then what is the rate of the melting of ice?
[Specific latent heat of fusion of ice = 80 cal/g]

1. 0.85 g/s
2. 1.92 g/s
3. 6.56 g/s
4. 5.65 g/s

Q. If a wire of resistance R is stretched twice its original length keeping volume constant then what will be its new resistance?

1. 4R
2. R/2
3. R/4
4. 2R

Q.

The commercial unit of electricity

Q. What is the commercial unit of energy? What is the SI unit of electrical energy? A body does 20 joules of work in 5 seconds. What is its power? [4 Marks]