Linear Expansivity

An iron rod of length 50 m and at a temperature of 60⁰C is heated to 70⁰C. Calculate its new length.

(Linear expansivity of iron = 1.2 x 10^-5 K^-1)

• 50.006 m

• 50.060 m

• 51.600 m

• 51.200 m

A brass rod is 2m long at a certain temperature. Calculate the linear expansion of the rod for a temperature change of 100 K. (Linear expansivity of brass = 1.8 x 10^-5 K^-1)

• 0.3600 m

• 0.1800 m

• 0.0360 m

• 0.0036 m

A metal rod of length 40.00 cm at 20⁰C is heated to a temperature of 45⁰C. If the new length of the rod is 40.05 cm, calculate its linear expansivity.

• 1.2 x 10^-5 K^-1

• 2.5 x 10^-5 K^-1

• 3.5 x 10^-5 K^-1

• 5.0 x 10^-5 K^-1

Steel bars, each of length 3.0 m at 28⁰C, are to be used for constructing a rail line. If the linear expansivity of steel is 1.0 x 10^-5 K^-1, what is the safety gap that must be left between successive bars if the highest temperature expected is 40⁰C ?

• 1.2 x 10^-1 cm

• 8.4 x 10^-2 cm

• 3.6 x 10^-2 cm

• 1.8 x 10^-2 cm

A wire, 20 m long, is heated from a temperature of 5⁰C to 55⁰C. If the change in length is 0.020 m, calculate the linear expansivity of the wire.

• 1.0 x 10^-3 K^-1

• 2.0 x 10^-4 K^-1

• 2.0 x 10^-5 K^-1

• 2.0 x 10^-6 K^-1