Question

A heater of resistance 10 ohm draws 15 amphere current from service mains for 2 hours having power 10 watt for 2 hours. Calculate.
1) the heat developed in the heater
2) powers of heaters

Answer 1

Answer:

4500 J; 2250 W

Explanation:

Given:

• R = 10 ohm
• I = 15 A
• t = 2 hrs

To Find:

• Heat developed in the heater = ?
• Power of the Heater = ?

Solution:

• We know that Heat energy, H = I*I*R*t = 15*15*10*2 = 2250*2 = 4500 J
• Power of Heater, P = energy ÷ time = 4500/2 = 2250 W

Answer 2

Given: Resistance = 10 Ohms, Current = 15 Amperes, Time = 2 hours, Power = 100 Watts.

To find: The heat developed in the heater and the power of the heater.

Answer:

Formula to find heat:

Heat = I^2Rt, where I is the current, R is the resistance and t is the time.

Substituting the respective values in the above formula,

H = 15^2*10*2 = 4500 Joules.

Now to find the power.

Power = Energy ÷ Time.

P = 4500 ÷ 2 = 2250 Watts.