Question

An iron wire with a diameter of 2 mm will be used to connect a voltage source to a 100kΩ resistor. Numbers for conductivity and resistivity can be found in the textbook.

(a) What is the current needed to flow through the resistor if the resistor is to produce 1 mW of heat?

Answer 1

To find the current needed to flow through the 100kΩ resistor, we need to calculate the resistance of the iron wire and then use Ohm's Law.

Step-by-step explanation:

To find the current needed to flow through the 100kΩ resistor, we need to calculate the resistance of the iron wire and then use Ohm's Law. The resistance of a wire can be calculated using the formula:

R = (ρ * L) / A

Where R is the resistance, ρ is the resistivity, L is the length of the wire, and A is the cross-sectional area of the wire.

Once we have the resistance of the wire, we can use Ohm's Law:

I = V / R

Where I is the current, V is the voltage, and R is the resistance.