Question

3.
A bar of iron is 10 cm at 20°C. At 19°C it will be (aFe = 11 * 10-6/°C)
(1) 11 * 10-6 cm longer
(2) 11 x 10-6 cm shorter
(3) 11 * 10-5 cm shorter
(4) 11 x 10-5 cm longer​

Answer 1

Answer:

Correct option is

C

11x10

−5

cm shorter

generally when we are reducing the temperature of the iron bar it will become shorter than before

change in lenghtl

2

=α(l

1

)(t

2

−t

1

)

= (11×10

−6

)(10)(19−20)

= 11×10

−6

(10)(−1)=11×10

−5

cm