set 3 MCQ Questions & Answers Detailed Explanation

Question : 1

Which of the following statement about molecular structure is correct?

a) Electron and proton are inside the nucleus and neutron revolve around the nucleus

b) Proton and neutron are inside the nucleus and electrons revolve around the nucleus

c) Neutron and electron are found inside the nucleus and protons revolves around the nucleus

d) Proton, neutron and electron all are inside the nucleus

Question : 2

Protons and neutrons are bound in a nucleus by the

a) long range ‘electromagnetic interaction’

b) short range ‘strong interaction’

c) short range ‘weak interaction’

d) long range ‘gravitational interaction’

Question : 3

One gram of which of the following contains largest number of oxygen atoms?

a) O₂

b) O₃

c) O

d) All contains same

Question : 4

While performing cathode ray experiments, it was observed that there was no passage of electric current under normal conditions. Which of the following can account for this observation ?

a) Carbon dioxide is present in air

b) Air is a poor conductor of electricity under normal conditions

c) Dust particles are present in air

d) None of these

Question : 5

The alpha particle carries two positive charges. Its mass is very nearly equal to that of

a) An atom of helium

b) Sum of masses of two positrons and two neutrons

c) Two protons

d) Two positrons are each positron carries a single positive charge

Question : 6

In an atom valence electron are present in

a) next to outermost orbit

b) first orbit

c) outermost orbit

d) any one of its orbit