Atransformer connected to a 120--v ac line is to supply 12.0v (rms) to a portable electronic device. the load resistance in the secondary is 4.70 ohms

1) what should the ratio of primary to secondary turns of the transformer be?

n1/n2 =

2) what rms current must the secondary supply?

i = a

3) what average power is delivered to the load?

p = w

4) what resistance connected directly across the source line (which has a voltage of 120? v ) would draw the same power as the transformer?

r = ohms

Ahair dryer is basically a duct in which a few layers of electric resistors are placed. a small fan pulls the air in and forces it through the resistors where it is heated. air enters a 1200 w hair dryer at 100 kpa and 22°c and leaves at 47°c. the cross-sectional area of the hair dryer at the exit is 60 cm2. neglecting the power consumed by the fan and the heat losses through the walls of the hair dryer, determine (a) the volume flow rate of air at the inlet and (b) the velocity of the air at the exit.