Question

When light bulbs A and B are connected in series to a battery, A glows brightly and B glows dimly. You remove bulb B so that the circuit is just the battery and bulb A and connect bulb B to an identical battery.With the two bulbs connected to identical batteries but in separate circuits, do they glow equally brightly now? a. Bulb A glows brighter b. The two bulbs glow equally brighty. c. Bulb B glows brighter.

Answer 1

Answer:

The bulb B glows brighter.

Explanation:

Given that,

A glows brightly and B glows dimly.

According to ohm's law,

Two light bulbs A and B are connected in series to a battery then the current will be same in both bulbs and the resistance is high of bulb A and low in bulb B.

If bulb A connect to a battery and bulb B connect to a same battery separately.

Then bulb B glows brighter because the resistance is high in bulb A so the current will be low.

The resistance is low in bulb B so the current will be high.

Hence, The bulb B glows brighter.

Answer 2

Answer:

Explanation:

When the two bulbs A and B are connected in series, the current is same in both the bulbs. Power is given by

P = i²R

so, as the bulb A is glowing more than the B, so the resistance of A is more than B.

Now they are connected seperately by two indentical batteries. The potential difference is same in both the bulbs.

Power is given by

P = V²/R

as the resistance of B is smaller than the resistance of A, so the brightness of bulb B is more than A.