The temperature coefficient of resistance of tungsten is 4.5 × 10-3 ° C -1 and that of germanium is -5 × 10-2 ° C -1. A tungsten wire of resistance 100 Ω is connected in series with a germanium wire of resistance R. The value of R for which the resistance of combination does not change with temperature is

Question

The temperature coefficient of resistance of tungsten is 4.5 × 10-3 ° C -1 and that of germanium is -5 × 10-2 ° C -1. A tungsten wire of resistance 100 Ω is connected in series with a germanium wire of resistance R. The value of R for which the resistance of combination does not change with temperature is (A) 9 Ω (B) 1111 Ω (C) 0.9 Ω (D) 111.1 Ω

Tardigrade Admin · Accepted Answer

R1 α1+R2 α2=0 (100)(4.5 × 10-3) =R(5 × 10-2) 0.9 × 10=R R=9 r

$9 Ω$

$1111 Ω$

$0.9 Ω$

$111.1 Ω$

$R_{1} α_{1} + R_{2} α_{2} = 0$
$(100) (4.5 \times 1 0^{- 3})$
$= R (5 \times 1 0^{- 2})$
$0.9 \times 10 = R$
$R = 9 r$

9Ω

1111Ω

0.9Ω

111.1Ω

R1​α1​+R2​α2​=0 (100)(4.5×10−3) =R(5×10−2) 0.9×10=R R=9r

$9 Ω$

$1111 Ω$

$0.9 Ω$

$111.1 Ω$

$R_{1} α_{1} + R_{2} α_{2} = 0$
$(100) (4.5 \times 1 0^{- 3})$
$= R (5 \times 1 0^{- 2})$
$0.9 \times 10 = R$
$R = 9 r$