Safety Fuse

Q.

Fuse is a safety device used in circuits which prevents damage to electrical appliances and avoids fire.

1. True

2. False

Q.

Name the type of current used in household supply.

Q.

What type of current we get at our homes ac or dc .

Q.

The fuse wire melts when high electric current passes through the circuit due to its:

1. high melting point

2. low melting point

3. high conductivity

4. low conductivity

Q.

Explain Domestic electric circuit? [5 MARKS]

Q. What are the role of live wire and neutral wire in domestic purpose

Q.

How do the (i) thickness and (ii) length of a fuse wire depend on its current rating?

Q. The working of electric fuse is based on:

1. Ohm’s law
2. Joule’s law of heating
3. Coulomb’s law
4. Faraday’s law

Q.

Which of the following is used as a safety device?

1. Fuse

2. Switch

3. Battery

4. Filament

Q.

In AC, the direction of current alters after every fixed interval of time, then why we have one wire termed as live wire and the other termed as neutral wire, both should have been termed as live or neutral wire.

Q.

List out the reason from the following for melting of a fuse wire.

1. Very high resistance of wire

2. Very low resistance

3. Material of the wire

4. Colour of the wire

Q. An electrical appliance has a rating of $5\text{kW},200V$. What should be the minimum current rating of the fuse to be used with the appliance?

1. $20A$
2. $26A$
3. $5A$
4. $15A$

Q. An electric fuse works on the:

(a) chemical effect of current
(b) magnetic effect of current
(c) lighting effect of current
(d) heating effect of current

Q.

A device which trips if the current in the circuit becomes exceedingly high is known as.

Q.

At the time of short circuit, the current in the rest of the circuit reduces substantially.

1. Reduces substantially

2. Does not change

Q.

Electricity is supplied to our houses in two separate circuits as

1. 5 A and 10 A

2. 5 A and 15 A

3. Can’t say

4. 10 A and 15 A

Q. What we used to protect the electric circuits from over loading and short circuit ?

1. capacitance
2. inductance
3. fuse wire
4. filament wire.

Q. Why do we connect our appliances at home in parallel?

Q. is used as a safety device to protect devices from large flow of current.

1. Battery
2. Cell
3. Fuse
4. Filament

Q.

At the time of short circuit, the current in the rest of the circuit ______ substantially.

1. remains constant

2. reduces

3. increases

4. None of the above

Q. What is the total power delivered to the circuit shown in figure ?

1. 220 W
2. 240 W
3. 200 W
4. 228 W

Q.

What is an electric fuse and what is its use?

Q. Which one of the following is true?

1. Current through different appliances is equal.
2. Current through different appliances is different.
3. Voltage through different appliances is different.
4. Power for different appliances is equal.

Q. Fuse of $3A,5A$ and $10A$ are available. Calculate and select the fuse for operating an electric iron of $1kw$ power at $220V$.

Q.

MCBs are connected to the

1. Neutral wire

2. Earth wire

3. Live wire

4. None of these

Q.

Fuse is a safety device used in circuits which prevents damage to electrical appliances and avoids fire.

1. False

2. True

Q. My mother was operating the washing machine on Sunday morning. Suddenly, she saw a spark coming out of the electric board and the electric current in the house failed. An electrician was called to look into the matter. What should he have noticed?

Q. Which of the following are characteristics of an electric fuse?

1. Low melting point
2. High melting point
3. Lesser thickness
4. Greater thickness

Q.

Question 24
What is the role of fuse, used in series with any electrical appliance? Why should a fuse with defined rating not be replaced by one with a larger rating?

Q. What is the role of fuse, used in series with any electrical
appliance? Why should a fuse with defined rating not be replaced
by one with a larger rating?