Processing math: 72%
Home / Aptitude Tests / Physics / A metal sheet of are...

A metal sheet of area 100cm2 was heated through 70&d...

A metal sheet of area 100cm2 was heated through 70°C. Calculate its new area if the linear expansivity of the metal is 0.000017K1.

A.

100.06 cm2

B.

100.12cm2

C.

100.24cm2

D.

100.36cm2

Correct answer is C

Formula: A2 = A1(1 + βθ)

where β = The area expansivity

θ = Change in temperature.

β = 2α

where α = linear expansivity of the body.

β = 2 x 0.000017 

= 0.000034 K1

A_2 = 100 (1 + (0.000034 x 70))

= 100(1 + 0.00238)

= 100(1.00238)

= 100.238 cm^2

= 100.24 cm^2 (to 2 d.p)