Carbon resistors, used in electronic circuits are marked for their value of resistance and tolerance by a colour code. A given resistor has colour scheme brown, red, green and gold. Its value in ohm is

Options

A. `52xx10^(6)pm10%`
B. `24xx10^(5)pm5%`
C. `12xx10^(4)pm10%`
D. `12xx10^(5)pm5%`

Answer

To determine the resistance value of a carbon resistor with the color code brown, red, green, and gold, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Color Code:**
- The color bands on the resistor are:
- 1st band: Brown
- 2nd band: Red
- 3rd band: Green
- 4th band: Gold

2. **Assign Numerical Values to Each Color:**
- According to the standard resistor color code:
- Brown = 1
- Red = 2
- Green = 5
- Gold = Tolerance (5%)

3. **Calculate the Resistance Value:**
- The resistance value is calculated using the formula:
\[ R = (AB) \times 10^C \]
- Where:
- A = 1 (from Brown)
- B = 2 (from Red)
- C = 5 (from Green)
- Plugging in the values:
\[ R = (1 \, 2) \times 10^5 \]
- This means:
\[ R = 12 \times 10^5 \, \text{ohms} \]
- Therefore, the resistance value is:
\[ R = 1.2 \, \text{MΩ} \, \text{(Megaohms)} \]

4. **Determine the Tolerance:**
- The tolerance for the resistor is given by the gold band, which is ±5%.

5. **Final Answer:**
- The value of the resistor is **1.2 MΩ ± 5%**.