Safety Fuse

Q.

What is an MCB ? Why it is preferred over a fuse?

Q. A fuse is made up of a ___ .

1. thick wire
2. thin wire
3. bad conductor of electricity
4. wire with a very high melting point

Q. An electric bulb works on the effect of electric current.

1. chemical
2. magnetic
3. heating
4. cooling

Q.

Which of the following is used to protect home appliances from high voltages/currents?

1. Fuse

2. An electric motor

3. Cell

4. Diode

Q.

Miniature Circuit Breaker or MCB is also known as___

1. a fuse

2. a resistance

3. a bulb

4. a coil

Q. Statement I: A fuse connected to an electrical circuit will blow off if the current succeeds the safe limit.​

Statement II: There is a maximum limit on the current which can safely flow through a fuse connected to an electric circuit.

1. Both the statements are correct
   
2. Statement 1 is correct and statement 2 is incorrect.
   
3. Statement 1 is incorrect and statement 2 is correct.
   
4. Both the statements are incorrect

Q.

Whenever there is an excessive flow of current in a household circuit:

1. One of the appliances acts as a fuse and protect other appliances from the excess current.

2. A tap switch passes this excess current to a bulb.

3. An MCB breaks the circuit, and protects all the appliances connected to the circuit.

4. The wiring in the circuit protects the appliance from this excess current.

Q.

In an electrical circuit, an electric appliance is duly earthed, but fuse is placed in neutral wire. If the electric appliance short circuits the fuse blows off.

Will it be safe to touch electric appliance when the fuse blows off?

Q.

State two properties of the material of fuse wire which makes it suitable for use.

Q. MCB stands for Circuit Breaker.

1. Miniature
2. Mini
3. Micro

Q.

What is meant by short-circuiting an electrical circuit?

Q. An electric fuse works on the:

1. Magnetic effect of current
2. Lighting effect of current
3. Heating effect of current
4. Chemical effect of current

Q.

A point of which either current starts or reaches finally after flowing through the complete circuit, Name it.

Q. Name a safety device used in the electric circuit. What is the function of safety device? [2 MARKS]

Q. The topology with highest reliability

1. bus topology
2. star topology
3. mesh topology
4. ring topology

Q.

What does a $5A$ rating on a fuse mean?

1. Burns down if I < $5A$

2. Melts if I > $5A$

3. Can function only if I = $5A$

4. Does not indicate anything

Q. protects the household devices from the damage caused by large electric currents.

1. Electric switch
2. Battery
3. Filament
4. Electric fuse

Q.

Why is fuse wire used in electric circuits?

1. To increase the current flow in the circuit.

2. To increase the voltage.

3. To prevent insulation.

4. For the protection of electrical appliances and circuit.

Q. An electric fuse used in households works on which principle of:

1. Joule's heating
2. Coulomb's law
3. Maxwell's law
4. Ohm's law

Q. Fuse works on the principle of ___________ effects of electric current.

1. sound
2. visual
3. heating
4. magnetic

Q.

An electrician is carrying out repairs in your house. He wants to replace a fuse with a piece of wire. ​​Would you agree? Explain.​​

Q.

Select the most appropriate option:

Statement 1: During a short circuit, two wires come in contact without the presence of resistance in between and a large amount of current flows through the circuit.

Statement 2: In case of overloading many devices are connected to the same circuit and hence a low current flows through the circuit.

1. Both statements are true

2. Statement 1 is true and Statement 2 is false

3. Both statements are false

4. Statement 1 is false and Statement 2 is true

Q.

What should be the characteristic of fuse wire

1. High melting point , high specific resistance

2. Low melting point, high specific resistance

3. High melting point , low specific resistance

4. Low melting point , high specific resistance

Q.

Which is the component that makes an electric circuit open in case of an excess current?

1. Switch

2. Fuse wire

3. Small iron rod

4. Battery

Q.

Explain the electric fuse and its use.

Q.

For a fuse rated at $5A$, the fuse melts if the current in the circuit exceeds $5A$.

1. True

2. False

Q.

Two identical fuses are rated $5A$If they are joined

1. in parallel, the combination acts as a fuse of rating $5A$

2. in parallel, the combination acts as a fuse of rating $10A$

3. in series, the combination acts as a fuse of rating $5A$

4. in series, the combination acts as a fuse of rating $10A$

Q.

Safety assurance in circuits is achieved by___.

1. a press button switch

2. a thick metal wire

3. a safety fuse

4. a thick graphite wire

Q. In which of the following cases, the fuse operates to break the circuit?

1. Underloading
2. Overloading
3. (b) and (c) above.
4. Short circuit

Q.

Which of the following is used as a safety device?

1. Fuse

2. Switch

3. Battery

4. Filament