Answer:
Power P = 360 W
Energy E = 0.72 kWh
Explanation:
Power can be expressed as a function of potential difference and current as;
Power = potential difference × Current
P = VI.............. 1
Given:
Potential difference V = 120 V
Current I = 3 A
Substituting the given values into equation 1
P = 120 × 2
P = 360 W
Therefore, the power usage of the device = 360 W
Energy is the product of potential difference, current and time.
Energy = Current×potential difference×time
E = iVt.............. 2
Given:
V = 120 V,
I = 3 A,
t = 2 hr.
Substitute into equation 2
E = 3×120×2 = 720 Wh ÷ 1000 kWh/Wh
E = 0.72 kWh
Therefore, the energy of the device in kWh = 0.72 kWh
Answer:
360 W, 0.72 kW-hour
Explanation:
Power = Voltage × Current
P = VI.............. Equation 1
Given: V = 120 V, I = 3 A.
Substitute into equation 1
P = 120(2)
P = 360 W.
Hence the power usage of the device = 360 W
Energy = Voltage×Current×time
E = VIt.............. Equation 2
Given: V = 120 V, I = 3 A, t = 2 hr.
Substitute into equation 2
E = 120(3)(2)/1000
E = 0.72 kW-hour
Hence the energy of the device in kWh = 0.72 kWh
