Question

you and your roommates are studying hard for you physics exam. you study late into the night and then fall into your bed for some sleep. you all wake early before the exam and scramble groggily around making breakfast. you can’t agree on what to have, so one of you cooks waffles on a 990 w waffle iron while another toasts bread in a 900 w toaster. you want to make a cup of coffee with a 650 w coffeemaker, and you plug it into the same power strip into which the waffle iron and toaster are plugged. will the 20 a circuit breaker trip? explain.

Answer 1

The circuit breaker will trip because the current drawn is in excess of its capacity

Step-by-step explanation:

The 20 A circuit breaker is designed to not carry current in excess of its capacity.

Total power demand on power strip = 900 + 990 + 650 = 2540 w

Let us assume a standard American voltage outlet of 120 V

Recall that electric power is

P = I x V

Where I is current, and

V = voltage.

For the 2540 W power drawn, the current I is

I = P/V = 2540/120 = 21.16 A

This is 1.16 A in excess of its capacity.