Question

two identical cells each of emf 1.5 v are connected in series to an ammeter and an unknown resistance. when the cells are in series, ammeter reading is 1 a, and when the cells are in parallel the ammeter reading is 0.6 a. the internal resistance of the cell is

Answer 1

When the identical cells are connected in series, the total resistance of the circuit is 3 ohms. When they are connected in parallel, the total resistance is 2.5 ohms. The internal resistance of the cells cannot be determined without additional information.

Step-by-step explanation:

When the two identical cells are connected in series, their EMFs add up, resulting in a total EMF of 3 volts (1.5V + 1.5V). The current flowing through the circuit is 1 ampere, as indicated by the ammeter reading. Using Ohm's Law (V = IR), we can determine the total resistance of the circuit by dividing the total EMF by the total current:

R = V/I = 3V/1A = 3 ohms.

Now, when the cells are connected in parallel, the EMFs stay the same (1.5 volts each), but the current splits between the two paths. The ammeter reading now shows a total current of 0.6 amperes. To find the unknown resistance, we can use Ohm's Law again:

R = V/I = 1.5V/0.6A = 2.5 ohms.

Since the internal resistance of the cells is not mentioned, we cannot directly calculate it based on the given information.