Q. A trough contains mercury to a depth of 3.6 cm. If some amount of mercury is poured in it then height of mercury in the trough will be
A) 3.6 cm
B) 7.2 cm
C) 6 cm
D) None of these
Explanation
(b) Let $A$ be the area of cross-section of through and $\rho$ be the density of mercury
Initial mass of mercury in trough
$= A \times 3.6 \times \rho$
Final mass of mercury in trough
$= A\ h^{'}\rho = (A \times 3.6 \times \rho) \times 2$
or $h^{'} = 7.2$ cm
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.