To a block of wood, a metal sphere is attached with the help of a string and the whole arrangement is dropped in a water container as shown in the figure.

If the wooden block floats in water, then which of the following statements is true?
(a) Upthrust on the wooden block is equal to its weight.
(b) Upthrut on the metal sphere is equal to its weight.
(c) Tension in the string is equal to its weight. of metal sphere.
(d) Tension in the string is less than the weight of metal sphere.

Explanation

Force acting on metal sphere:
(i) Tension T upwards
(ii) Weight `W_(m)` downwards
(iii) Upthrust `U_(m)` upwards
SO, `T+U=W_(m)`
`T=W_(m)-U`
So, tension in the string is less than the weight of metal sphere Option (d) is correct.
Force acting on the wooden block.
(i) Tension T, downwards
(ii) Weight `W_(b),` downwards
(iii) Upthrust, `U_(h)`, upwards
`T+W_(b)=U_(b)`
So, none of the other options, a,b and c are correct