Question

exam lesson name: electricity and electronics
exam number: 700798rr
exam guidelines
exam instructions
question 2 of 20 :
select the best answer for the question.

1. which of the following does not affect the electrical resistance of a body?

a. length of the body
b. bodies directly surrounding the body
c. material composing the body
d. temperature of the body
mark for review (will be highlighted on the review page)
<< previous question
next question >>

Explanation:

To determine which factor does not affect electrical resistance, we recall the formula for resistance \( R=
ho\frac{l}{A} \), where \(
ho \) is resistivity (dependent on material and temperature), \( l \) is length, and \( A \) is cross - sectional area.

• Option A: Length (\( l \)) is in the resistance formula, so it affects resistance.
• Option B: Bodies directly surrounding the body do not appear in the resistance formula or the physical principles that determine resistance (resistance depends on the material's resistivity, length, cross - sectional area, and temperature of the material itself).
• Option C: The material of the body determines the resistivity (\(

ho \)) of the material, so it affects resistance.

• Option D: Temperature affects the resistivity (\(

ho \)) of most materials, so it affects resistance.

Answer:

B. Bodies directly surrounding the body