Question

If 20 coulomb charge is flowing in 0.5 second from a point in an electric circuit when the value of electric current in amperes will be
A) $10$
B) $40$
C) $0.005$
D) $0.05$

Answer 1

Hint: The current can be defined as the rate of flow of charge through the circuit. The movement of charges will produce the current. If the charges are stationary then there is no current. Since the charge and time is given current can be found easily.

Complete step by step answer:
Given the charge flowing through the circuit is $Q = 20\;{\text{C}}$ in time $t = 0.5\;{\text{s}}$ .
 The particle will experience a force when placed in an electric field. This property is responsible for the charge of a particle. The charged particle that is electrons and their movement causes the current produced in the circuit. One Ampere of current is the one coulomb of charge through the circuit in one second. Thus when the particle is stationary, it only has charge. But when it starts to move it will have current.
The expression for current flowing through the circuit is given as,
$I = \dfrac{Q}{t}$
Where, $Q$ is the charge flowing through the circuit and $t$ is the time.
Thus the rate of charge flowing through the circuit is the current.
Substituting the values in the above expression,
$
\Rightarrow I = \dfrac{{20\;{\text{C}}}}{{0.5\;{\text{s}}}} \\
\Rightarrow I = 40\;{\text{A}} \\
$

$\therefore$ The current will be $40\;{\text{A}}$. Hence, the correct answer is option (B).

Note:
The current produced can be Alternating current (AC) or direct current (DC). The major difference is that when charges move in both directions, it is alternating current. If the charges move in only one direction, then it is direct current.