A silver wire has a resistance of 1.6 Ω . At 25.5°C, and a resistance of 2.5 Ω . at 100°C, then temperature coefficient of resistivity of silver is

Question

A silver wire has a resistance of 1.6 Ω . At 25.5°C, and a resistance of 2.5 Ω . at 100°C, then temperature coefficient of resistivity of silver is (A)  5.55× 10-3 °C  (B)  7.55× 10-3 °C (C)  11.75× 10-2 °C  (D)  15.5× 10-3 °C

Tardigrade Admin · Accepted Answer

R2=R1[1+α(T2-T1). ((R2-R1)/(T2-T1)) × (1/R1)=α ((2.5-1.6)/(100-25.5)) × (1/1.6)=α (0.9/74.5) × (1/16)=α 0.0075503=α α=7.55 × 10-3 ° C

Q. A silver wire has a resistance of $1.6 Ω$ . At $25. 5^{\circ} C,$ and a resistance of $2.5 Ω$ . at $10 0^{\circ} C,$ then temperature coefficient of resistivity of silver is

$5.55 \times 1 0^{- 3}^{\circ} C$

$7.55 \times 1 0^{- 3}^{\circ} C$

$11.75 \times 1 0^{- 2}^{\circ} C$

$15.5 \times 1 0^{- 3}^{\circ} C$

$R_{2} = R_{1} [1 + α (T_{2} - T_{1})$
$\frac{( R _{2} - R _{1} )}{( T _{2} - T _{1} )} \times \frac{1}{R _{1}} = α$
$\frac{( 2.5 - 1.6 )}{( 100 - 25.5 )} \times \frac{1}{1.6} = α$
$\frac{0.9}{74.5} \times \frac{1}{16} = α$
$0.0075503 = α$
$α = 7.55 \times 1 0^{- 3}^{\circ} C$

Q. A silver wire has a resistance of 1.6Ω . At 25.5∘C, and a resistance of 2.5Ω . at 100∘C, then temperature coefficient of resistivity of silver is

5.55×10−3∘C

7.55×10−3∘C

11.75×10−2∘C

15.5×10−3∘C