A copper rod of 88 cm and an aluminium rod of unknown length have thei

1.	A copper rod of 88 cm and an aluminium rod of unknown length have their increase in length independent of increase in temperature.The length of aluminum rod is:(αCu = 1.7 × 10-5 K-1 and αAl = 2.2 × 10-5 K-1)(A) 88 cm (B) 68 cm (C) 6.8 cm(D) 1 13.9 cm
Answer» (B) 68 cm L_Cu α_Cu ∆T = L_Al α_Al ∆T ∴ 88 × (1.7 × 10^-5) = L_Al(2.2 × 10^-5) ∴ L_Al= \(\frac{88\times1.7}{2.2}\) ∴ L_Al= 68 cm

A copper rod of 88 cm and an aluminium rod of unknown length have their increase in length independent of increase in temperature.The length of aluminum rod is:(αCu = 1.7 × 10-5 K-1 and αAl = 2.2 × 10-5 K-1)(A) 88 cm (B) 68 cm (C) 6.8 cm(D) 1 13.9 cm

Answer»

(B) 68 cm

L_Cu α_Cu ∆T = L_Al α_Al ∆T

∴ 88 × (1.7 × 10^-5) = L_Al(2.2 × 10^-5)

∴ L_Al= \(\frac{88\times1.7}{2.2}\)

∴ L_Al= 68 cm