the turn ratio of transformer is 1:10.A battery of 12v is connected to the primary coil,what is the voltage drop across the secodary coil

Transformers won't increase DC voltage.

To find the voltage drop across the secondary coil of a transformer with a turn ratio of 1:10, you need to use the formula:

Voltage ratio = Number of turns in the secondary coil / Number of turns in the primary coil

Given that the turn ratio is 1:10, this means that there are 10 turns in the secondary coil for every 1 turn in the primary coil. So, the voltage ratio is:

Voltage ratio = 10 / 1 = 10

Now, to find the voltage drop across the secondary coil, you multiply the voltage applied across the primary coil by the voltage ratio.

Voltage drop across secondary coil = Voltage across primary coil * Voltage ratio

Voltage across primary coil = 12V (given in the question)

Voltage drop across secondary coil = 12V * 10 = 120V

Therefore, the voltage drop across the secondary coil is 120V.

Vs/Vp = Ns/Np

Traditionally 1:10 would mean the secondary coil has 1/10 the number of turns.