Question

There is some water in a beaker placed on the pan of a spring balance. If we dip our finger in this water without touching the bottom of the beaker ___________

(a) The reading will be the same

(b) The reading will increase

(c) The reading drops to zero

(d) The beaker falls down

I had been asked this question in examination.

This intriguing question comes from Friction and Forces topic in portion Laws of Motion of Engineering Physics I

Answer 1

Correct choice is (b) The reading will increase

To explain I would say: The water exerts upthrust on the finger and the finger will exert an equal force of reaction on the water in the downward direction. Thus the reading will increase.