A resistor is marked as `98Omega-0.5` W, the largest voltage can be put in this is

Options

A. 3V
B. 5V
C. 7V
D. 9V

Explanation

To find the largest voltage that can be applied to a resistor marked as `98Ω` and `0.5W`, we can use the relationship between power, voltage, and resistance. The formula we will use is:

\[ P = \frac{V^2}{R} \]

Where:
- \( P \) is the power (in watts),
- \( V \) is the voltage (in volts),
- \( R \) is the resistance (in ohms).

### Step-by-Step Solution:

1. **Identify the given values**:
- Resistance \( R = 98 \, \Omega \)
- Power \( P = 0.5 \, W \)

2. **Rearranging the power formula**:
We need to find \( V \). Rearranging the formula gives us:
\[ V^2 = P \times R \]

3. **Substituting the known values**:
Substitute \( P \) and \( R \) into the equation:
\[ V^2 = 0.5 \, W \times 98 \, \Omega \]

4. **Calculating the product**:
Calculate \( 0.5 \times 98 \):
\[ V^2 = 49 \]

5. **Taking the square root**:
To find \( V \), take the square root of both sides:
\[ V = \sqrt{49} = 7 \, V \]

6. **Conclusion**:
The largest voltage that can be applied to the resistor is \( 7 \, V \).

### Final Answer:
The largest voltage that can be put in this resistor is **7 volts**.

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