Answered

A tungsten wire has resistance R at 20°C. A second tungsten wire at 20°C has twice the length and half the cross-sectional area of the first wire. In terms of R, the resistance of the second wire is

(1)R/2

(2)2R

(3)R

(4)4R

Verified Answer :

MonsieurPengu

The resistance is 4 times the resistance of the first wire. the formula is R = pl/A with p being resistivity, l length and A area. So if you double length and half area, which botv result in more resistance, you get p2/0.5 or 4 (p can be abandoned because it is the same. We take standard length and area as 1)

shubhamchouhanvrVT

The value of the resistance of the second wire will be equal to \(R_2=4R_1\)

What is resistance?

The resistance of a wire is defined as the restriction to the flow of the charge or current offered by the wire.

Now it is given in the question that

Second tungsten wire has resistance with a length twice and area half.

The formula for the resistance is given as

\(R=\dfrac{\rho l}{A}\)

Now for first tungsten wire

\(R_1=\dfrac{\rho l}{A}\)

For second tungsten wire

\(R_2= \dfrac{\rho 2l}{\dfrac{A}{2}}\)

\(R_2=\dfrac{4 \rho l}{A}\)

\(R_2=4R_1\)

Hence the value of the resistance of the second wire will be equal to \(R_2=4R_1\)

To know more about Resistance follow

https://brainly.com/question/17563681

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