JEE PYQ: Properties Of Matter Question 18
Question 18 - 2019 (12 Jan 2019 Shift 1)
A load of mass M kg is suspended from a steel wire of length 2 m and radius 1.0 mm in Searle’s apparatus experiment. The increase in length produced in the wire is 4.0 mm. Now the load is fully immersed in a liquid of relative density 2. The relative density of the material of load is 8. The new value of increase in length of the steel wire is:
(1) 3.0 mm
(2) 4.0 mm
(3) 5.0 mm
(4) Zero
Show Answer
Answer: (1)
Solution
$\Delta l \propto F$. In liquid: $T’ = Mg\left(1 - \frac{\rho_l}{\rho_b}\right) = Mg\left(1 - \frac{2}{8}\right) = \frac{3}{4}Mg$
$\Delta l’ = \frac{3}{4} \times 4 = 3$ mm
BETA
