In: Physics
A kitchen toaster is connected to a potential difference of 180 volt. It has a resistance of 3.6 kΩ. If it operates for the time 4 h, how much energy (in Joule) does it consume? Round off to one decimal point.
Concept :-
Joules law states that, the energy consumed or heat generated (Q) in an electric material is equal to the product of square of current (I) flowing through it, resistance (R) of the equipment and time (t) taken to flow the current. The mathematical expression is :-
. - (1)
Where I - current, R - resistance, t - time in seconds (s)
We know that, according to ohm's law voltage (V) is equal to current (I) and resistance (R)
- (2)
Substitute eq(2) in eq(1)
Solution :-
Given that, potential difference (voltage), V = 180 volts
Resistance of the toaster, R = 3.6 k = 3600
Operating time, t = 4 h = 4 × 60 × 60 = 14400 seconds
Energy consumed by the toaster,
Energy consumed by the toaster, Q = 129600.0J or 129.6 kJ