Question

The spring balance $A$ reads $2 \, kg$ with a block of mass $m$ suspended from it. A balance $B$ reads $5 \, kg$ when a beaker with liquid is put on the pan of the balance. The two balances are now so arranged that the hanging mass is inside the liquid in a beaker as shown in the figure.

• A. The balance $A$ will read more than $2\,kg$
• B. The balance $B$ will read less than $5\,kg$
• C. The balance $A$ will read less than $2\,kg$ and $B$ will read more than $5\,kg$
• D. The balance $A$ will read more than $2\,kg$ and $B$ will read less than $5\,kg$

Answer 1

Answer: (C)

The effective weight of the block in the liquid will become less than $2\,kg$ due to buoyancy of liquid. As a result of which $A$ will read less than $2\,kg$ .
As the body immersed in liquid has some effective weight acting downwards so the reading of $B$ will be more than $5\,kg$ .