Question

A transformer has an efficiency of 80% and works at 100 volt and 4 kw. If the secondary voltage is 240volt calculate the primary and secondary currents

Answer 1

Hi..

Hope this helps u!!

Answer 2

The current in primary coil is 40 A and secondary coil is 13.3 A

• Given,

                  Efficiency = 80%

                  Input power = 4000 W

                  Input voltage = 100 V

                  Output voltage = 240 V

Calculating primary current

• We know that,

                  $P_{in} = I_{p}V_{p}$

                 4000 = $I_{p}$ x 100

                   $I_{p}$ = 40 A

Calculating secondary current

• Also,

                   $Efficiency = \frac{P_{out} }{P_{in} }$

                                       $= \frac{I_{s} V_{s} }{I_{p}V_{p} }$

                         $\frac{80}{100} = \frac{I_{s} (240)}{(40)(100)}$

                         $I_{s}$ = 13.3 A