Question

17. The resistivity of the material of a wire is 4x10-5 12 cm. If the resistance of the wire is
141 and its diameter is 1mm, the length of the wire is
A. 25cm
D. 27.5m
B. 47cm
E. 5m
C. 2.7cm
T

Answer 1

Answer:

Explanation:

Given,

specific resistance,p= 4❌10^-5

resistance,R= 14 ohm

radius= d/2 =1/2 =0.5 mm

=0.05 cm

Now,Area of wire= ♊r^2

= 3.14 ❌ 0.05❌ 0.05

= 785❌10^-5.

Let's,the length of wire be l

As, specific resistance,p=

R❌a➗ l

4❌10^-5 = 14 ❌785* 10^-5

➗ l

length,l= 14 ❌ 785* 10^-5

➗ 4* 10^-5

= 10,990 /4

= 2747.5 cm

= 27. 5 metre.

Answer 2

Answer:

the answer of this question is 27.5