How much power rating is needed for a 3.3 kohm resistor carrying 50 mA?

To determine the necessary power rating for a resistor, we can use the power formula which relates power (P), resistance (R), and current (I). The formula is given by:

[ P = I^2 \times R ]

In this case, we have a resistor with a resistance of 3.3 kΩ (which is 3300 ohms) and a current of 50 mA (which is 0.050 A). We can now calculate the power:

1. Square the current:

[

I^2 = (0.050)^2 = 0.0025 , A^2

]

2. Multiply by the resistance:

[

P = 0.0025 , A^2 \times 3300 , ohms = 8.25 , W

]

The calculated power is 8.25 W. Therefore, the required power rating for the resistor must be higher than this value to ensure safe operation and to accommodate any potential factors such as temperature or additional power surges.

Hence, a resistor with a power rating of 10 W would be appropriate, making it capable of handling the calculated power safely without the