Question

A step up transformer is used to :

• A. increase the current and increase the voltage
• B. decrease the current and increase the voltage
• C. increase the current and decrease the voltage
• D. decrease the current and decrease the voltage

Answer 1

The correct option is B decrease the current and increase the voltage

We know that

$\frac{V\left(input\right)}{V\left(output\right)}=\frac{N\left(input\right)}{N\left(output\right)}$

in step up transformer , N(input) < N(output) so accordingly, V(output) increases.
Now, power is conserved
but power = voltage x current = Vi
so V(input) x i(input) = V(output) x i(output)
hence, current i.e., i(output) decreases