Question

Aneesh was performing an experiment with two bulbs rated as $60$ W - $220$ V and $100$ W - $220$ V. When he connected the two bulbs in series to a $440$ V supply, one of the bulbs got fused. The amount of current flowing through the circuit is ______A.

• A. $0.1256$
• B. $0.3409$
• C. $0.27$
• D. $0.72$

Answer 1

The correct option is B $0.3409$

We know that $R=\frac{V^2}{P}$

So, The resistance of first bulb $=\frac{220\times 220}{60}\Omega$

Similarly, The resistance of second bulb $=\frac{220\times 220}{100}\Omega$

When he connected the two bulbs in series to a 440440 V supply, second bulb got fused as it has lower resistance.

Also, the total resistance $=\frac{220\times 220}{60}\Omega$ $+\frac{220\times 220}{100}\Omega =1290.67\Omega$

Now, the current flowing $=\frac{440}{1290.67}=0.3409A$

Therefore, B is correct option.