An iron block is on a boat which floats in a pond. The block is thrown into the water. The level of water in the pond will be

Options

A. equal to the earlier level
B. less than the earlier level
C. more than the earlier level
D. depends on how large the block is

Answer

B

Explanation

When iron block was floating, it displaces `V_(1)` volume of water such that weight of this `V_(1)` volume of water is equal to weight of block. But since density of iron is more than density of water, this volume `V_(1)` will be greater than volume `V_(2)` or iron block. When iron block sinks in the pond, it displaces water of volume equal to its own volume `V_(2)`.
Since `V_(1) gt V_(2)` displaced volume in first case was more than displaced volume in second case. Hence, level will fall.