Q. 63.7( 146 Votes )

# A copper wire has

Answer :

Given:

The radius of wire,
r = Area of the cross-section can be calculated by, The Resistivity of the resistor, Resistance, R= 10 Formula used:
Resistance, Where,
ρ is the resistivity of the copper wire
L is the length of the copper wire
A is the area of the cross-section of the wire
Solving the above equation for the length Putting the values in the above equation, we get Thus, the length of copper wire required to make 10 resistance will be 122.5 meters.

(b)   If the diameter is twice, D'=2D
Where,
D' is the new diameter
D is the initial diameter
Then, according to the question, the new diameter is twice the initial diameter.
D' = 2(0.5mm)  = 1mm

Now, the new radius R' =D (Initial diameter of the cross-section)= D'/2 = 0.5 mm
As we know, Putting the values in the above formula, we get Thus, Resistance, R=2.5 Ω
Thus, if we twice the diameter of the copper wire the resistance become the quarter part of the initial resistance.

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos  Heating Effect of Electric Current40 mins  Resistors in Parallel39 mins  Ohm's Law43 mins  Resistors in Series42 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation view all courses RELATED QUESTIONS :

In a series combiScience Lab Manual

What is the equivScience Lab Manual

Why are copper anScience Lab Manual