Question

. A brass and an iron rod are each 1 meter long at 0 o C. Difference in their length at 100o C is (brass = 19 10-6 / o C and iron = 12  10-6 / oC) a) 0.7 cm *b) 0.07 cm c) 7 cm d) 0.007 cm

Answer 1

Answer:

Abrar sand and iron rod reach 1 metre long at zero degree celsius difference in their length at hundred degree celsius is the 0.7 CM answer

Answer 2

Given:

Initial length, Lb1 = Li1 = 1 m

Initial temp, T1 = 0°C

Final temp, T2 = 100°C

αb = 19 × 10⁻⁶ /°C

αi = 12 × 10⁻⁶ /°C

To Find:

The difference in the length of brass and iron rods at 100°C.

Calculation:

- Change in temp, ΔT = 100 - 0 = 100°C

- New length of brass rod is given as:

Lb2 = Lb1 (1 + αb ΔT)

⇒ Lb2 = 1 (1 + 19 × 10⁻⁶ × 100)

⇒ Lb2 = 1 + 19 × 10⁻⁴

⇒ Lb2 = 1.0019 m

- New length of iron rod is given as:

Li2 = Li1 (1 + αi ΔT)

⇒ Li2 = 1 (1 + 12 × 10⁻⁶ × 100)

⇒ Li2 = 1 + 12 × 10⁻⁴

⇒ Li2 = 1.0012 m

- Difference in their length = Lb2 - Li2

⇒ ΔL = 1.0019 - 1.0012

⇒ ΔL = 0.0007 m

⇒ ΔL = 0.07 cm

- So, the correct answer is option (b) 0.07 cm.