$B_1, B_2$ and $B_3$ are three identical bulbs connected as shown in Figure 12.8. When all the three bulbs glow, a current of 3A is recorded by the ammeter A.

How much power is dissipated in the circuit when all the three bulbs glow together?

$220 \mathrm{~V}-60 \mathrm{~W}$ ও $220 \mathrm{~V}-80 \mathrm{~W}$

এর ২টি বাল্ব 1টি 220V উৎসের সাথে শ্রেণিতে যুক্ত আছে।

When the balance point is obtained in the potentiometer, a current is drawn from

The resistance of the filament of an electric bulb changes with temperature. If an electric bulb rated $220 \ V$ and $100 \ W$ is connected to $(220\times 0.8) \ V$ source, then the power would be :

With a potentiometer null point were obtained at $140\ cm$ and $180\ cm$ with cells of emf $1.1\ V$ and one unknown $X$ volts. Unknown emf is