Question

An electric iron of 1 kilowatt is operated 220 Volt find which of the following fuses that respectively rated at 1 ampere,3 ampere and 5 ampere can be used in it

Answer 1

Answer:power = 1 kW

V=220volt

Current : A= 1 A

B=5A

C=3A

We know that v=ir

For current A

V=ir

220=1×r

R=220 ohm

For current B

V=ir

220=5×r

R=220/5

R=44 ohm

For current C

V=ir

220=3×r

R=220/3

R=73.3 ohm

If we compare the resistance of all three current B has the lowest resistance and it can be used as fuse.

Explanation: