What is the total resistance of a parallel circuit that contains two resistors having values of 220 ohm and 470 ohm? A. 220 ohm B. 150 ohm C. 445 ohm D. 690 ohm E. None of the above

220 ohm
150 ohm
445 ohm
690 ohm E. None of the above

The correct answer is $\boxed{\text{C}}$, 445 ohms.

To find the total resistance of a parallel circuit, we use the following formula:

$$R_T = \frac{1}{R_1} + \frac{1}{R_2} + \cdots + \frac{1}{R_n}$$

In this case, we have two resistors, $R_1 = 220 \Omega$ and $R_2 = 470 \Omega$. Substituting these values into the formula, we get:

$$R_T = \frac{1}{220 \Omega} + \frac{1}{470 \Omega} = 445 \Omega$$

Option A is incorrect because it is the resistance of one of the resistors in the circuit. Option B is incorrect because it is the average of the resistances of the two resistors. Option C is correct because it is the total resistance of the parallel circuit. Option D is incorrect because it is the sum of the resistances of the two resistors. Option E is incorrect because it is not one of the possible answers.