Question

In the figure given, the electric current flowing through the$5k\Omega$ resistor is$\text{'}x\text{'}mA.$

The value of $x$ to the nearest integer is ________.

Answer 1

Step 1: Given data

$I=xmA$

Resistor= $5k\Omega$

Step 2: Draw a diagram

Step 3: Calculate the total resistance from point A to point B

The resistances are connected in parallel.

Therefore, $\frac{1}{R}=\frac{1}{R_1}+\frac{1}{R_2}+\frac{1}{R_3}$. Where, R= Total resistance and R₁, R₂, R₃ = Individual resistance.

So, $\frac{1}{R}=\frac{1}{3}+\frac{1}{3}+\frac{1}{3}$

$\frac{1}{R}=\frac{3}{3}$

$\frac{1}{R}=1$

Step 4: Calculate the total resistance of the electrical circuit

The resistances are connected in series.

Therefore, $R=R_1+R_2+R_3$, Where, R= Total resistance and R₁, R₂, R₃ = Individual resistance.

So, $R=1+5+1$

$R=7$.

Step 5: Calculate the required current

According to Ohm's Law,

$$\begin{gathered} I=\frac{V}{R} \\ I=\frac{21}{7} \\ I=3 \end{gathered}$$

Hence, the required current is $3mA$.