Question

What type of transformer is used in a $6V$ bed lamp?

Answer 1

As the household supply in India is $220V-240V$ $AC$ so to use a bed lamp having rating $6V$ a $step-down$

transformer will be required with a $rectifier$ to convert $6V$ $AC$ to $6V$ $DC$ if the lamp is $DC$ lamp.

If supply at home is $240V$ then we would be needing a transformer with $turn$ $ratio$ $=\frac{6}{240}$