Problem 28 - A Complete Resource Book in Physics for JEE Main

Question

When cells are connected in series (A) the EMF increases. (B) the potential difference decreases. (C) the current capacity increases. (D) the current capacity decreases.

Step-by-Step Solution

Answer

When cells are connected in series, the EMF increases because the voltages across the cells add up while the current capacity remains the same. So, the correct statement is (A) the EMF increases.

Step 1: Recall Connection in Series#

When two or more cells are connected in series, their positive terminals are connected to the negative terminals of the next cell. In this configuration, the voltages across the cells add up while the current capacity remains the same. Now let's analyze the given options one by one.

Step 2: Option A: EMF increases#

When cells are connected in series their EMFs (Electromotive force) are added up. In this case, the effective EMF becomes the sum of all the individual cells' EMFs. So the statement (A) the EMF increases, is correct.

Step 3: Option B: Potential difference decreases#

The potential difference across the cells in series is equal to the sum of the potential difference across each cell. So, when connected in series, the potential difference does not decrease. Therefore, this statement is false.

Step 4: Option C: Current capacity increases#

When cells are connected in series, the current capacity remains the same. The arrangement does not increase the current capacity. So, this statement is false.

Step 5: Option D: Current capacity decreases#

As mentioned earlier, when cells are connected in series, their current capacity remains the same. It does not decrease. Thus, this statement is also false. Among all the given options, only Option A (the EMF increases) correctly describes what happens when cells are connected in series.