12- An electric clothes dryer is rated at 4,800 W. How much energy does it use in 35 min?

13- Which costs more, running a 1,300-W hair dryer for 8 min or leaving a 50-W lamp on overnight (10 h)? Select answer:

a) the lamp

b) the hair dryer

14-The resistance of an electric heater is 40 when connected to 120 V. How much energy does it use during

50 min of operation?

15- The charger cord used to recharge a cell phone contains a transformer that reduces 240 V AC to 4 V AC. For each 1,050 turns in the input coil, how many turns are there in the output coil? (Round your answer to at least one decimal place.)

16-The blackbody radiation emitted from a furnace peaks at a wavelength of7.010^-6m(0.0000070m).What is the temperature inside the furnace?

17-The generator at a power plant produces AC at 25,000 V. A transformer steps this up to 325,000 V for transmission over power lines. If there are 2,150 turns of wire in the input coil of the transformer, how many turns must there be in the output coil?