In the given circuit, if power rating of heater is 1000 Watt at 100 Volt, find the resistance R in figure so that heater produces power of 62.5 W.

Step-by-step solution

Power rating of heater, P =1000 ~W Voltage rating of heater, V =100 ~V Resistance of heater, R ₁= V ^2 P = (100)^2 1000 =10 According to question, power dissipated in heater, P ^ =62.5 ~W Voltage ( V ^ . ) across heater can be calculated as aligned & P ^ = ( V ^ )^2 R ₁ ( V ^ )^2= P ^ R ₁=62.5 10 & V ^ =25 ~V (across heater) & aligned Voltage across 10 resistor, V ^ =100-25=75 ~V Current in 10 resistor = V ^ 10 = 75 10 =7.5 ~A Current in heater resistor = V ^ 10 = 25 10 =2.5 ~A So, current in R =7.5-25=5 ~A Now, V