*Question T5D11:
What is the voltage across a 10-ohm resistor if a current of 1 ampere flows through it?*  

*Correct Answer is  B: 10 volts*  

### AI Response: (may contain errors)  

To find the voltage across a resistor when a current flows through it, we can use Ohm's Law, which states:

$$V = I \times R$$

where:
- $V$ = voltage in volts
- $I$ = current in amperes
- $R$ = resistance in ohms

In this case:
- $I = 1 \text{ A}$
- $R = 10 \text{ ohms}$

Now, substituting the values into the formula:

$$V = 1 \text{ A} \times 10 \text{ ohms} = 10 \text{ volts}$$

### Explanation of the Correct Answer:
- The correct answer is **10 volts** because, according to Ohm's Law, when 1 ampere of current flows through a 10-ohm resistor, the voltage across it is calculated to be 10 volts.

### Explanation of Incorrect Choices:
- **Choice A: 1 volt**
  - This is incorrect because it suggests that only 1 volt is produced by the 1 ampere of current through a 10-ohm resistor, which does not follow Ohm's Law.
  
- **Choice C: 11 volts**
  - This is incorrect as it implies an additional voltage that is not accounted for by the current and resistance given. The calculation does not support this value.
  
- **Choice D: 9 volts**
  - This is also incorrect because it underestimates the voltage across the resistor. The calculation clearly shows that the voltage must be 10 volts.

### Summary:
- Use Ohm's Law to relate voltage, current, and resistance.
- For a 10-ohm resistor with 1 ampere of current, the voltage is 10 volts.