Question

Question 14 (i)
Compare the power used in the $2\Omega$ resistor in each of the following circuits:
(i) a 6 V battery in series with $1\Omega$ and $2\Omega$ resistors.

Answer 1

(i) Potential difference, V = 6 V
$1\Omega$ and $2\Omega$ resistors are connected in series.
Therefore, equivalent resistance of the circuit, $R=1\Omega +2\Omega =3\Omega$
According to Ohm’s law, V = IR
Where, I is the current flowing through the circuit
$I=\frac{6}{3}=2A$
This current will flow through each component of the circuit because there is no division of current in series circuits.
Hence, current flowing through the $2\Omega$ resistor is 2 A.
Power is given by the expression, $P=(I{)}^{2}R=(2{)}^2\times 2=8W$