Question

Two spheres of volume $250cc$ each but of relative densities $0.8$ and $1.2$ are connected by a string and the combination is immersed in a liquid. Find the tension in the string is:
$(g=10m/s^2)$

• A. $5.0N$
• B. $1N$
• C. $1.5N$
• D. $2N$

Answer 1

The correct option is A $5.0N$

The heavier sphere will be down and the lighter sphere will be up.

∴∴ The tension on heavier sphere will be upward.

Let the density of liquid be 8.

Then for lighter sphere

(500×10−6×600g)(500×10−6×600g)+T$

=(500×10−6)×ρ×g=(500×10−6)×ρ×g -------(1)

For heavier sphere

(500×10−6×1200g)(500×10−6×1200g)-T$

=(500×10−6)×ρ×g=(500×10−6)×ρ×g -------(2)

Solving (1) and (2) we get,

2T=3×10−12T=3×10−1

T=1.5×10−1T=1.5×10−1

=0.15N=0.15N

Answer :0.15 N