Answer to Question #333828 in Physics for Dale

Question

a. Will a 1200-watt hair dryer operate on a 120-volt line if the current is limited to 15 amperes by a safety fuse? Can two hairdryers operate on this line?

b. Choose from 3A, 5A, 13A, and 30A: Which fuse is the most suitable for a circuit in which a refrigerator rated at 2.0 kW is to be connected to a 220 V supply?

solution please thank you.

Answer 1

(a)

$I=\frac{P}{V}=\frac{1200}{120}=10\:\rm A<15\: A$

One hair dryer will operate. Two -- no.

(b)

$I=\frac{P}{V}=\frac{2000}{220}=9.1\:\rm A$

The most suitable fuse for a circuit is 13 A.