please answer this question ASAP
Answers
Explanation:
Part I
Given:
Resistivity =1.6×10^-8 ohm m
Resistance= 10 ohm
Diameter of wire = 0.5mm
=0.0005 m
Radius of wire=D/2
= 0.0005/2
= 0.00025 m
Area of cross section = πr^2
= 3.14(0.00025^2)
=7.85^-7 m^2
To find :
length
Formula :
R=resistivity×L/A
Solution:
10 = 1.6×10^-8 ×L/7.85^-7
L= 10 ×7.85^-7/1.6 ×10^-8
L= 10×7.85/ 1.6×10^-1
L= 7.85/1.6×1^-1
L = 7.85/1.6
L=4.9 m
Part II
Given:
Resistivity= 1.6×10^-8 ohm m
Length = 4.9m
Diameter = 0.5×2
=1 mm
= 0.001 m
Area of cross section= πr^2
= 3.14 × 0.001
= 0.00314 m^2
To find :
Resistance
Formula:
Resistance = Resistivity×L/A
Solution:
R= 1.6×10^-8×4.9/0.00314
R= 2.49681529^-5 ohm
Part III
Change in the resistance=
10- (2.49681529^-5)
= 9.98 ohm