Fuse

The primary function of a fuse is to

• Open the circuit

• Protect the appliance

• Protect the line

• Prevent excessive currents from flow through the circuit

The fuse rating is expressed in terms of

• Current

• Voltage

• VAR

• KVA

Fuses have got advantages of

• Cheapest type of protection

• Inverse time current characteristic

• No Maintenance

• Current limiting effect under short-circuit conditions

• All of the above

Fusing factor should be

• Equal to zero

• Less than now

• Equal to one

• More than one

Fuses can serve upto a current of

• 25 A

• 50 A

• 75 A

• 100 A

Which among these is the least expensive protection for over current in low voltage system?

• Rewirable fuse.

• Isolator.

• Circuit breaker.

• Air breaker switch.

For a current upto 10A which material is used as the fusing element?

• Copper

• Silver

• Alloy of lead and tin

• Zinc

H.R.C. fuses has

• High rating of current

• High rupturing capacity

• High resistance capacity

• None of these

On which off the following effects of electric current a fuse operates?

• Photoelectric effect

• Electrostatic effect

• Heating effect

• Magnetic effect

A fuse in a motor circuit provides protection against

• Overload

• Short-circuit and overload

• Open circuit, short-circuit and overload

• None of the above