Tag: electric current and its effects

Questions Related to electric current and its effects

The circuit breaker device which can be used in place of a fuse is called

physics electric current and its effects electric fuse electrical fuse and mcb fuse

  1. CBD

  2. MCB

  3. MCD

  4. CBF

Show answer
Correct Option: B
Explanation:

Answer is B.

Fuse boxes contain safety devices called fuses or circuit breakers - MCB (Miniature Circuit Breaker) which are designed to prevent an excess of electric current entering your house by only allowing a certain maximum current to flow in. When the electrical current is too large, an electromagnet attracts a spring loaded switch which breaks the circuit and cuts the power supply. The switch must be reset before any current can flow again.

In an electric circuit, a fuse is connected :

physics electric current and its effects electric fuse electrical fuse and mcb fuse

  1. in the live wire

  2. in the neutral wire

  3. in the earth wire

  4. Any of these

Show answer
Correct Option: A
Explanation:

Answer is A.

The live wire and neutral wire, coming from the electric pole, enter a box fitted just outside our house which has a main fuse F1. The fuse is connected in series with the live wire. This is done so because it is only the live wire which has a high potential of 220 volts unlike the neutral wire which carries zero potential.

What is immaterial for an electric fuse?

physics electric current and its effects electric fuse electrical fuse and mcb fuse

  1. Its length

  2. Its radius

  3. Its specific resistance

  4. Current flowing through it

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Correct Option: A
Explanation:

Its length is immaterial for an electric fuse fuse is used to avoid danger due to high current if high current is passed through the fuse it burns and disconnect the power supply the thickness of fuse determines how much current can be pass hence fuse of any length can be used but it's thickness should be proper

Fuses are connected in ________ to the live wire:

physics electric current and its effects electric fuse electrical fuse and mcb fuse

  1. parallel

  2. series

  3. either way

  4. None

Show answer
Correct Option: B
Explanation:

Answer is B.

The live wire and neutral wire, coming from the electric pole, enter a box fitted just outside our house which has a main fuse F1. The fuse is connected in series with the live wire. This is done so because it is only the live wire which has a high potential of 220 volts unlike the neutral wire which carries zero potential.

The essential requirements of a fuse wire are ___________.

physics electric current and its effects electric fuse electrical fuse and mcb fuse

  1. High resistance and high melting point

  2. High resistance and low melting point

  3. Low resistance and low melting point

  4. Low resistance and high melting point

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Correct Option: B
Explanation:

The fuse wire is made of zinc, copper, silver, aluminum, or alloys to provide stable and predictable characteristics. Fuse should be of low resistance and low melting point as per the requirement current rating for overcurrent protection.

Fuse wire is a

physics electric current and its effects electric fuse electrical fuse and mcb fuse

  1. tin-lead alloy

  2. copper-lead alloy

  3. tin-copper alloy

  4. silver-lead alloy

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Correct Option: A
Explanation:
Fuse wire is made of a tin-lead alloy and not copper because of the following reasons:

1. They have high resistance due to high resistance the wire heats up quickly, when large current flows.

Heating power of wire $P=i^2R$

2. They have low melting point which melts and breaks off the circuit if the current is larger than the safety limit.



In Fuse wire a copper wire can not be used because it has a high melting point. Copper wire will not melt easily when a high electric current passes through it and may harm the electrical appliances attached to it.

State whether true or false.
A fuse is always connected to the neutral wire in a household circuit.

physics electric current and its effects electric fuse electrical fuse and mcb fuse

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

A fuse is always connected to the neutral wire.T his statement is false. Fuse is connected to live wire.

Fuse is always connected to the ______ wire.

physics electric current and its effects electric fuse electrical fuse and mcb fuse

  1. live

  2. neutral

  3. earth

  4. green

Show answer
Correct Option: A
Explanation:

Fuse is always connected to live wire. The purpose of a fuse is to protect the wiring and equipment from overloading

State whether true or false.
When a short-circuit takes place, the fuse wire melts and breaks the electric circuit.

physics electric current and its effects electric fuse electrical fuse and mcb fuse

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Yes,given statement is true, because short-cicuiting is an  excessive current flow in the power source through the short due to which the fuse wire melts and breaks the electric circuit.

Therefore, A is correct option

A fuse is connected to the

physics electric current and its effects electric fuse electrical fuse and mcb fuse

  1. Live wire

  2. Neutral wire

  3. Earth wire

  4. None of these

Show answer
Correct Option: A
Explanation:

Fuses are always connected in series with the components to be protected from overcurrent, so that when the fuse blows (opens) it will open the entire circuit and stop current through the components. A fuse connected in one branch of a parallel circuit, of course, would not affect current through any of the other branches.