Which of the following waves can propagate in a vacuum?
1.Radio waves
2.Light waves
3.X-rays
4.Ultrasonic waves
Select the correct answer using the codes given below

When two mercury drops are brought into contact, they merge to form a bigger drop because liquids have a tendency to possess

Which of the following statements is/are true?
I) Sound is a form of energy
II) Sound stops when vibration of an object stops
III) Sound is a transverse wave
IV) Sound travels better in a heavy gas than in a light gas

Consider the following statements
1.Atom bomb is based upon the principle of uncontrolled nuclear fusion
2.Hydrogen bomb is based upon the principle of uncontrolled nuclear fission
3.Nuclear reactor is based upon the principle of controlled nuclear fission
Which of the statements given above is/are correct?

Raindrops are spherical due to

Inside an aeroplane, flying at a high altitude

A stone is thrown into a deep lake. As it sinks deeper and deeper into the water, the upthrust acting on it

The atmosphere exerts enormous pressure on us. But we do not feel it because

The quality of a sound depends upon the
I) size of the vibrating body
II) material of the vibrating body
III)overtones produced
IV) shape of the vibrating body

Cyclotron is a device which