Quick question to do with Vp/Vs=Np/Ns (physics).

Hey, im practicing my modular past papers for my modular exams tomorrow for science.

on Question 22 of the paper im doing on physics:

Q:

The mains voltage is 230 V and the input voltage to the phone is 4.6V.
The Number of turns on the primary coil is 800.
The number of turns on the secondary coil is
either:
16
160
174
40,000

From my knowledge, i've got 230/4.6 = 800/?

so i times 230x800 then divide by 4.6 to make 40,000 right?

If i'm wrong please correct me and tell me where i went wrong.

Apologies, if i have typed this out in a confusing manner.

Reply 1

Excalibur

15

MisterE

Hey, im practicing my modular past papers for my modular exams tomorrow for science.

on Question 22 of the paper im doing on physics:

Q:

The mains voltage is 230 V and the input voltage to the phone is 4.6V.
The Number of turns on the primary coil is 800.
The number of turns on the secondary coil is
either:
16
160
174
40,000

From my knowledge, i've got 230/4.6 = 800/?

so i times 230x800 then divide by 4.6 to make 40,000 right?

If i'm wrong please correct me and tell me where i went wrong.

Apologies, if i have typed this out in a confusing manner.

I'm not entirely sure, but I got 16... if you do Vp/Vs = Np/Ns, then it will come out as 230/4.6 = 800/x (as you did). To get x, you do 800x4.6, and divide by 230 to get 16.

Reply 2

MisterE

OP

1

Thanks for the reply, i also think the answer is 16 now. As i thought, 40,000? If voltage is 230v and the turns is 800. How could 4.6 be 40,000? Seems 16 is more logical ! Thanks alot !