Question 410: AC fundamentals

Question

A step down transformer is used to reduce the main supply from '$$V_1$$' volt to '$$V_2$$' volt. The primary coil draws a current '$$\mathrm{I}_1$$' $$\mathrm{A}$$ and the secondary coil draws '$$\mathrm{I}_2$$' A. $$(\mathrm{I}_1<\mathrm{I}_2)$$. The ratio of input power to output power is

Accepted Answer

The power in an electrical circuit is given by the product of voltage and current. For a transformer, we can say that the input power $$P_{	ext{in}}$$ is the product of the primary voltage $$V_1$$ and the current $$I_1$$ flowing through it, which gives us:
$$
P_{	ext{in}} = V_1 I_1
$$
Similarly, the output power $$P_{	ext{out}}$$ is the product of the secondary voltage $$V_2$$ and the current $$I_2$$ flowing through it:
$$
P_{	ext{out}} = V_2 I_2
$$
The question asks for the ratio of input power to output power, which can be represented as:
$$
\frac{P_{	ext{in}}}{P_{	ext{out}}} = \frac{V_1 I_1}{V_2 I_2}
$$
Comparing the given options with our derived formula, we can see that
Option B
exactly matches our result:
$$
	ext{Option B:} \quad \frac{V_1 I_1}{V_2 I_2}
$$
Therefore,
Option B
is the correct answer.

Answer

$$\frac{V_1 V_2}{I_1 I_2}$$

Answer

$$\frac{V_1 I_1}{V_2 I_2}$$

Answer

$$\frac{\mathrm{I}_1 \mathrm{I}_2}{\mathrm{~V}_1 \mathrm{~V}_2}$$

Answer

$$\frac{\mathrm{V}_1 \mathrm{I}_2}{\mathrm{~V}_2 \mathrm{I}_1}$$

AC fundamentals

A step down transformer is used to reduce the main supply from '$V_1' volt to 'V_2' volt. The primary coil draws a current '\mathrm{I}_1' \mathrm{A} and the secondary coil draws '\mathrm{I}_2' A. (\mathrm{I}_1<\mathrm{I}_2)$. The ratio of input power to output power is

Choose the correct answer: