*Question T5D04:
What is the resistance of a circuit in which a current of 3 amperes flows when connected to 90 volts?*  

*Correct Answer is  B: 30 ohms*  

### AI Response: (may contain errors)  

To find the resistance of a circuit when a current of 3 amperes flows with a voltage of 90 volts, 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

We can rearrange this formula to solve for resistance:

$$
R = \frac{V}{I}
$$

Now, substituting the given values:

$$
R = \frac{90 \text{ volts}}{3 \text{ amperes}} = 30 \text{ ohms}
$$

### Explanation of the Correct Answer:
- The correct answer is **30 ohms** because we calculated the resistance using the correct application of Ohm's Law. With a voltage of 90 volts and a current of 3 amperes, the resistance is indeed 30 ohms.

### Explanation of Incorrect Choices:
- **A: 3 ohms**  
  This choice is incorrect because it suggests a much lower resistance than calculated. If the resistance were 3 ohms, the current would be much higher than 3 amperes for 90 volts.

- **C: 93 ohms**  
  This choice is incorrect as it does not follow from the calculation. A resistance of 93 ohms would imply a different current for the same voltage, which does not match the given current of 3 amperes.

- **D: 270 ohms**  
  This choice is also incorrect. A resistance of 270 ohms would result in a much lower current than 3 amperes when connected to 90 volts, as per Ohm's Law.

### Summary:
- Use Ohm's Law to find resistance: $R = \frac{V}{I}$.
- For this problem, $R = \frac{90 \text{ volts}}{3 \text{ amperes}} = 30 \text{ ohms}$ is the correct calculation.