Question

What is the percentage change in length of 4m iron rod if its temperature changes by 200°C.
(a iron = 2 x 10^-5/°C)
O 0.2%
O 0.4%
O 0.6%
O 0.5%​

Answer 1

We have to find the percentage change in length of 4m iron rod if its temperature changes by 200°C. coefficient of iron is 2 × 10¯⁵/°C.

solution : change in length is given by, ∆L = L₀α∆T

⇒fractional change = ∆L/L₀ = α∆T

⇒percentage change = ∆L/L₀ × 100 = 100α∆T

here α = 2 × 10¯⁵/°C and ∆T = 200°C

so, percentage change in length of iron rod = 100 × 2 × 10¯⁵ × 200

= 4 × 10⁴ × 10¯⁵ = 0.4 %

Therefore the correct option is (B) 0.4 %

also read similar questions : Why a brown coating is formed on the iron rod when iron rod is kept dipped in copper sulphate solution for sometime? Wha...

https://brainly.in/question/2218504

An iron rod of lenght 30cm is heated through 50 kelvin calculate its increase in lenght (linear expansivity of iron=1.2 ...

https://brainly.in/question/17700596