You plan to take your hair blower to europe, where the electrical outlets put out 240v instead of the 120v seen in the united states. the blower puts out 1700w at 120v. a) what could you do to operate your blower via the 240v line in europe? which one is it? step up ? sted down? use a step_up transformer with n2/n1= 2.use a step_down transformer with n2/n1= 1/2.b) what current will your blower draw from a european outlet? c) what resistance will your blower appear to have when operated at 240 ?

A) 2.Use a step_down transformer with N2/N1= 1/2.

We have:

- Input voltage of the electrical outlet:

- Output voltage desired for using the hair blower:

So, in order to use the hair blower, we need to decrease the voltage. This can be done by using a step-down transformer, which has a larger number of turns in its primary coil compared to the secondary coil. The transformer equation states that:

where

is the number of turns in the primary coil

is the number of turns in the secondary coil

here we have

So, the transformer we need to use should have

(b) 7.08 A

In a transformer, the power input is equal to the output power. So we can write:

where

is the power drawn from the outlet

is the power put out from the hair blower

Here we know

So we have

and we can rewrite the power as product of the voltage times the current:

since we know also , we can find the current drawn from the outlet:

(c)

The resistance that the blower will appear to have when operated at 240 V can be found by using the formula:

(1)

where:

P = 1700 W is the power

is the rms voltage

R is the resistance

We use the rms voltage instead of the peak voltage (240 V) because the current in the outlet is an AC current. The rms voltage is given by

So now we can re-arrange eq.(1) to find the apparent resistance:

Re-arranging the equation, we can solve to find the resistance: