The resistance of a 3m length of cable is 2.7Ω. Determine :(a) The resistance of a 5m length of the same cable (b) the length of the same wire when the resistance is 6.3 Ω.
Answers
Answered by
1
Please refer to the attachment for the solution....
Hope you get that right....
Attachments:
Answered by
0
Explanation:
Formula used :
R = pL/A ,
where R is the resistance, p is the resistivity, L is the length and A is the area of cross section.
ATQ;
2.7 = 3p/A
=> p/A = 2.7/3
The ratio of p/A will remain constant since the same wire is used.
Case (1)
L = 5m
=> p/A = R1/5
=> R/5 = 2.7/3
=> R1 = 4.5 ohms
Case (2)
R2 = 6.3 ohms
==> p/A = 6.3/L2
=> 2.7/3 = 6.3/L2
=> L2 = 7 metres
Similar questions