1. A blow-dryer and a vacuum cleaner each operate with a voltage of 120 V. The current rating of the blow-dryer is 10 A, and that of the vacuum cleaner is 5.0 A.
(a) Determine the power consumed by the blow-dryer.
W
(b) Determine the power consumed by the vacuum cleaner.
W
(c) Determine the ratio of the energy used by the blow-dryer in 13 minutes to the energy used by the vacuum cleaner in one-half hour.
Ebd / Evc =
2. The rms current in a copy machine is 7.75 A, and the resistance of the machine is 13.4 ?.
(a) What is the average power?
W
(b) What is the peak power delivered to the machine?
W
3. A light bulb is connected to a 240-V wall socket. The current in the bulb depends on the time t according to the relation I = (2.828 A) sin[(157.0 Hz)t].
(a) What is the frequency of the alternating current?
Hz
(b) Determine the resistance of the bulb's filament?
?
(c) What is the average power delivered to the light bulb?
W