Question

What is the resistance of a heating element when the current through it is 1.20 A and it is consuming electrical energy at a rate of 240 W?

Answer 1

Answer:

R=166.67Ω

Explanation:

Power is the rate of doing work and its unit is Watt.

P = IV ........................equation 1

voltage is the product of current and resistance.

V=IR

substitute V=IR into equation 1

Power = I*IR

power =I²R

divide power by I square to get R

R=$\frac{power}{I^{2} }$

power =240W ,  I=1.2A  

R=  240/ 1.2²

R =240/1.44

R=166.67Ω

Answer 2

Answer:

166.67Ω

Explanation:

The resistance (R) of a device is related to the current (I) flowing through the device and the rate of electrical energy, which is power(P), as follows;

P = I² x R       ----------------------(i)

From the question, the following are given;

P = rate of electrical energy (also called power) = 240W

I = current through the element = 1.20A

Substitute these values into equation(i) as follows;

240 = (1.20)²  x R

240 = 1.44 x R

Solve for R;

R = 240 / 1.44

R = 166.67Ω

Therefore, the resistance of the heating element is 166.67Ω