Question

electronics information
in a closed circuit, when a short power cord is replaced with a long power cord,
which of the following increases?
a voltage
b insulation
c resistance
d conductivity
click the button or type the letter next to your answer.

Explanation:

Step1: Recall the resistance formula

The resistance formula is \(R =
ho\frac{l}{A}\), where \(
ho\) is the resistivity (a property of the material), \(l\) is the length of the conductor, and \(A\) is the cross - sectional area.

Step2: Analyze the effect of length on resistance

When the power cord is replaced (assuming the material \(
ho\) and cross - sectional area \(A\) remain the same), as \(l\) (length) increases (from short to long cord), according to the formula \(R=
ho\frac{l}{A}\), the resistance \(R\) increases.

Step3: Analyze other options

• Voltage: In a simple circuit (assuming ideal voltage source and no other changes in the circuit except the cord length), the source voltage remains constant.
• Insulation: Insulation is a property related to the material's ability to prevent current leakage and is not affected by the length of the conducting part of the cord in a simple replacement scenario.
• Conductivity: Conductivity \(\sigma=\frac{1}{

ho}\), and since \(
ho\) (resistivity) is a material property and not affected by the length of the cord, conductivity remains the same.

Answer:

C. resistance