Physics Questions and Answers

Which of the following properties is NOT exhibited by sound waves?

An object is placed 30 cm in front of a concave mirror of focal length 20cm. Calculate the distance between the object and the image.

Which of the following statement(s) is/are correct about the isotopes of an elements? They have the same

I. chemical properties
II. nucleon number
III proton number

Which of the following statement(s) is/are correct?

I. When a liquid expands its density falls
II. When a mercury-in-glass thermometer is placed in a hot liquid, the mercury level first descends and then rises.
III. The apparent expansion of a liquid is greater than its real expansion.

A ball of mass m moving at velocity u collides with another ball of equal mass at rest. If the two balls move off together after the impact, calculate their common velocity.