If the wire is stretched to make its length 4 times, then its specific resistance will be:(a) sixteen times(b) uncharged(c) four times(d) 1/4th

To find the specific resistance of a wire when it is stretched to make its length 4 times, we need to consider the relationship between length and specific resistance.

The specific resistance of a wire is given by the formula:

R = ρ * (L/A)

Where R is the specific resistance, ρ is the resistivity of the material, L is the length of the wire, and A is the cross-sectional area of the wire.

In this case, if the length of the wire is stretched to 4 times its original length, we can denote the original length as L and the stretched length as 4L.

Now, let's consider the specific resistance of the wire before stretching, denoted as R1:

R1 = ρ * (L/A)

And the specific resistance of the wire after stretching, denoted as R2:

R2 = ρ * (4L/A)

To compare R1 and R2, we can divide R2 by R1:

R2/R1 = (ρ * (4L/A)) / (ρ * (L/A))

Simplifying the equation, we can cancel out the resistivity ρ and the cross-sectional area A:

R2/R1 = (4L/A) / (L/A)

R2/R1 = 4L/L

R2/R1 = 4

Therefore, the specific resistance of the wire when it is stretched to make its length 4 times is four times the original specific resistance.

So, the correct answer is (c) four times.