Transformer windings and voltage

[sparkle123]

A transformer is constructed with 200 windings on the primary coil, and 800 windings on the secondary coil. The primary coil is connected to a car battery with a potential difference of 12 V. After a few seconds, what is the voltage across the secondary coil?

The answer is 0, but why? I thought that 4 times the windings on the secondary coil would result in four times the voltage...so the answer would be 48 V. Where am I wrong? Thanks!

 

[cjl]

What kind of power does a car battery supply? Also, how does a transformer work? Think about that for a while and it might help...

 

[sparkle123]

Ah well a battery would be DC and I think that the voltage is only proportional to turn ratio for AC transformers. I don't know how DC transformers work :$