A wire has resistance of 3.1 Ω at 30° C and 4.5 Ω at 100° C . The temperature coefficient of resistance of the wire is

Question

A wire has resistance of 3.1 Ω at 30° C and 4.5 Ω at 100° C . The temperature coefficient of resistance of the wire is (A) 0.0012° C-1 (B) 0.0024° C-1 (C) 0.0032° C-1 (D) 0.0064° C-1

Tardigrade Admin · Accepted Answer

Given, R 2= 4 . 5 Ω R 1= 3 . 1 Ω T 1= 3 0 ° C T 2= 1 0 0 ° C T 2- T 1=( 1 0 0 - 3 0 )° C = 7 0 ° ⇒ 4.5=3.1[1+α(70)] ⇒ 70 α=(4.5/3.1)-1 α=(4.5-3.1/3.1 × 70) α=6.45 × 10-3 α=0.0064° C -1

Q. A wire has resistance of $3.1 Ω$ at $3 0^{\circ} C$ and $4.5 Ω$ at $10 0^{\circ} C$ . The temperature coefficient of resistance of the wire is

$0.001 2^{\circ} C^{- 1}$

$0.002 4^{\circ} C^{- 1}$

$0.003 2^{\circ} C^{- 1}$

$0.006 4^{\circ} C^{- 1}$

Q. A wire has resistance of 3.1Ω at 30∘C and 4.5Ω at 100∘C . The temperature coefficient of resistance of the wire is

0.0012∘C−1

0.0024∘C−1

0.0032∘C−1

0.0064∘C−1

Given, R2​=4.5Ω R1​=3.1Ω T1​=30∘C T2​=100∘C T2​−T1​=(100−30)∘C =70∘ ⇒4.5=3.1[1+α(70)] ⇒70α=3.14.5​−1 α=3.1×704.5−3.1​ α=6.45×10−3 α=0.0064∘C−1

Q. A wire has resistance of $3.1 Ω$ at $3 0^{\circ} C$ and $4.5 Ω$ at $10 0^{\circ} C$ . The temperature coefficient of resistance of the wire is

$0.001 2^{\circ} C^{- 1}$

$0.002 4^{\circ} C^{- 1}$

$0.003 2^{\circ} C^{- 1}$

$0.006 4^{\circ} C^{- 1}$