In This post you will get answer of Q.
A transformer is used to light $140, W$, $24, V$ lamp from a $240,V$ ac mains. If the main current is $0.7, A$, the efficiency of the transformer is
Solution:
Output power $= 140,W$
Input power $= 240 times 0.7 = 168 ,W$
Efficiency $=frac{output ,power}{input, power}times100$
$=frac{140}{168}times100$
$=83.3%$
Solution:
Output power $= 140,W$
Input power $= 240 times 0.7 = 168 ,W$
Efficiency $=frac{output ,power}{input, power}times100$
$=frac{140}{168}times100$
$=83.3%$