Question

What is the power produced by an appliance marked ‘240 V, 2A ‘ ?
A. 8.3 Mw
B. 60 W
C. 120 W
D. 480 W

Answer 1

The energy liberated per second in a device is called its power. The electrical power delivered by an electrical device is given by voltage times the current . If the current enters the higher potential point of the device then the power is consumed by it ( acting as a load ) . I f the current enters the lower potential point then the device supplies power ( i.e acting as a source )

Complete step-by-step solution: Here, to calculate power we will use the formula,
$P = I.V$
Where ,$P$is the power produced by an appliance
$I$is the current supplied through that appliance
$V$ is the potential difference across the appliance.
Now,
Given ,
Voltage V =240 Volt and current I = 2A
$P = 2 \times 240 = 480W$
The power produced by an appliance marked ‘240 V, 2A ‘ is $480W$.
Hence option (D) is the correct answer.

Note:- Electric charges in motion constitute an electric current . Any medium having practically free charges, free to migrate is a conductor of electricity. The electric charge flows from higher potential energy states to lower potential energy states . Positive charge flows from higher to lower potential and negative charge flows from lower to higher.
Metals such as gold , silver , copper , aluminium etc are good conductors.
Electric current in a conductor :- In the absence of potential difference across a conductor , no net current flows through a cross- section. When a potential difference is applied across a conductor the charge carrier ( electrons ) flow in a definite direction which constitutes a net current in it. These electrons are accelerated by electric fields in the conductor produced by potential difference across the conductor. They move with a constant drift velocity.