Physics Past Questions and Answers

Which of the following statements is correct? Silvered walls of a vacuum flask are used to prevent

A concave lens of focal length 20cm form an image 1/2 the size of the object. The object distance is

The diagram shows lens arrangement in

In a given circuit, the cell P has an emf 1.5V and an unknown internal resistance while cell Q has an emf 2.0V and an internal resistance of 1 ohm if the ammeter reads 50m A, Then r is equal to

An air column 10cm in length is trapped into the sea end of a capillary tube by a 15cm column of mercury with the tube held vertically as shown above. On inverting the tube the air column becomes 15cm long. The atmospheric pressure during the experiment is