Question

A microwave oven running at 70 % efficiency delivers 950 W of energy per second to the interior. Part A Find the power drawn from the source. Express your answer using two significant figures.

Answer 1

`P_i\approx1.4* 10^3\ W`

Step-by-step explanation:

Given:

• power output of the oven,
  `P_o=950\ W`

• efficiency of the oven,
  `\eta=70\%`

We know that the efficiency is given as:

`\eta=(P_o)/(P_i)`

where:

`P_i=` power taken from the source as input to the oven

`0.7=(950)/(P_i)`

`P_i=(950)/(0.7)`

`P_i=1357.1429\ W`

`P_i\approx1.4* 10^3\ W`