A speech signal of `3 kHz` is used to modulate a carrier signal of frequency `1 MHz`, using amplitude modulation. The frequencies of the side bands will be

Options

A. 1.003 MHz and 0.997 MHz
B. 3001 KHz and 2997 KHz
C. 1003 KHz and 1000 KHz
D. 1MHz and 0.997MHz

Explanation

To find the frequencies of the sidebands generated by amplitude modulation (AM) of a speech signal, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Given Frequencies:**
- Modulating signal frequency (speech signal): \( f_m = 3 \text{ kHz} = 0.003 \text{ MHz} \)
- Carrier signal frequency: \( f_c = 1 \text{ MHz} \)

2. **Determine the Upper and Lower Sideband Frequencies:**
- The upper sideband (USB) frequency can be calculated using the formula:
\[ f_{USB} = f_c + f_m \]
- The lower sideband (LSB) frequency can be calculated using the formula:
\[ f_{LSB} = f_c - f_m \]

3. **Calculate the Upper Sideband Frequency:**
- Substitute the values into the USB formula:
\[ f_{USB} = 1 \text{ MHz} + 0.003 \text{ MHz} = 1.003 \text{ MHz} \]

4. **Calculate the Lower Sideband Frequency:**
- Substitute the values into the LSB formula:
\[ f_{LSB} = 1 \text{ MHz} - 0.003 \text{ MHz} = 0.997 \text{ MHz} \]

5. **Final Result:**
- The frequencies of the sidebands are:
- Upper Sideband (USB): \( 1.003 \text{ MHz} \)
- Lower Sideband (LSB): \( 0.997 \text{ MHz} \)

### Summary:
The sideband frequencies generated by the amplitude modulation of a 3 kHz speech signal with a 1 MHz carrier signal are:
- Upper Sideband: \( 1.003 \text{ MHz} \)
- Lower Sideband: \( 0.997 \text{ MHz} \)