In the circuit diagram given below the heat produced in the 5 Ω resistor due to a current flowing in it is 42 joule per second. What will be the heat produced in 4 Ω resistor?

HEAT IN 5 OHM RESISTOR  IS 42J/S MEANS 42 W SO BY FORMULA P=V²/R


42=V²/5
V²=210
V=4.5 V 
NOW IN RESISTOR 4 OHM 
USING SAME FORMULA BUT THERE RESISTANCE WE TAKE 4 OHM
SO P = 4.5 x 4.5 /  4
P =20.25/4
   = 5.625 W OR 5.625 J/S