Question

In the circuit diagram given below. Find



(i) Total resistance of the circuit

(ii) Total current flowing in the circuit

(iii) Potential difference across $R_1$

4. Define one ohm.

5. Define one ampere of current. [5 MARKS]

Answer 1

Each point: 1 Mark

1. For total resistance $8\Omega$ and $12\Omega$ are connected in parallel.

Their equivalent resistance comes in series with $7.2\Omega$ resistance as shown in fig.



With $7.2\Omega$ and $4.8\Omega$ in series

$R_s=7.2+4.8=12\Omega$

Total circuit resistance = 12 ohms

2. For total current

Total circuit resistance, R = 12 ohm

Potential difference applied, V = 6 V

I = ?

From Ohm's law $R=\frac{V}{I}$

$I=\frac{V}{R}$

$I=\frac{6}{I2}=0.5$

Total circuit current = 0.5 A

3. For potential difference across $R_1$

$R=\frac{V}{I}$

$V=IR$

$V_1=I{R}_1$

$V_1=0.5\times 7.2$

= 3.6 V

Potential difference across, $V_1=3.6V$

4. For one volt potential difference across a conductor, if current flowing is 1 Ampere resistance of the conductor is 1 ohm.

5. If one coulomb of charge flows through a conductor in one second, the current flowing through the conductor is known as one ampere (1A).