Xiao Ming uses an electric energy meter to measure the electric power of a household appliance. When only the appliance in the circuit works, the measured energy consumption is 0.3kw · h within 20min, which may be () A. Microwave oven B. electric fan C. television D. radio

From P = wt: P = 0.3kw · h2060h = 0.9Kw; among the above four kinds of household appliances, the only one with power close to 900W is microwave oven

What is the experimental principle of measuring the electric power of electrical appliances with an electric energy meter

The experimental principle is w = Pt, P = w / T. The ratio of the consumed electric energy w in a certain time t is the average power of the consumer