Q.
A spring balance, $A$ reads 2 kg with a block $m$ suspended from it. A balance $B$ reads 5 kg when a breaker filled 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 as shown in figure. In this situation
A) The balance $A$ will read more than 2 kg
B) The balance $B$ will read more than 5 kg
C) The balance $A$ will read less than 2 kg and $B$ will read more than 5 kg
D) The balance $A$ and $B$ will read 2 kg and 5 kg
Explanation
(c) The reading of balance $A$ will decrease due to the upward thrust caused b buoyancy. The upthrust will be equal to the weight of water displaced. The net downward force due to mass immersed in water will add to effective weight of the system. So, the reading of balance $B$ will increase
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.