If the frequency of alternating potential is 50Hz then the direction of potential, changes in one second by –

Options

A. 50 times
B. 100 times
C. 200 times
D. 500 times

Answer

To solve the problem, we need to determine how many times the direction of an alternating potential changes in one second when the frequency is given as 50 Hz.

### Step-by-Step Solution:

1. **Understanding Frequency**:
The frequency (f) of an alternating current is defined as the number of cycles per second. In this case, the frequency is given as 50 Hz.

2. **Calculating the Time Period (T)**:
The time period (T) is the duration of one complete cycle of the alternating current. It is calculated using the formula:
\[ T = \frac{1}{f} \]
Substituting the given frequency:
\[ T = \frac{1}{50 \text{ Hz}} = 0.02 \text{ seconds} \]

3. **Determining Direction Changes in One Cycle**:
In one complete cycle of an alternating current, the direction of the potential changes twice: once from positive to negative and once from negative back to positive.

4. **Calculating Direction Changes in One Second**:
To find out how many times the direction changes in one second, we need to determine how many cycles fit into one second. Since the time period is 0.02 seconds, the number of cycles in one second is:
\[ \text{Number of cycles in 1 second} = \frac{1 \text{ second}}{T} = \frac{1}{0.02} = 50 \text{ cycles} \]

5. **Calculating Total Direction Changes**:
Since each cycle results in 2 direction changes, the total number of direction changes in one second is:
\[ \text{Total direction changes} = 50 \text{ cycles} \times 2 = 100 \text{ changes} \]

### Conclusion:
Thus, the direction of the alternating potential changes **100 times** in one second.

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