Physics Online Test - 1

Question: 1

An egg when placed in ordinary water sinks but floats when placed in brine. This is because

(A) Density of brine is less than that of ordinary water

(B) Density of brine is equal to that of ordinary water

(C) Density of brine is greater than that of ordinary water

(D) None of these

Question: 2

Which one of the following planets is said to be “twin sister” of the Earth?

(A) Mars

(B) Mercury

(C) Venus

(D) Jupiter

Question: 3

Which one among the following lasers is used in cancer treatment?

(A) Semiconductor laser

(B) He-Ne laser

(C) CO₂ laser

(D) Semiconductor laser

Question: 4

Optical fibres mainly used in communication is based on

(A) total internal reflection

(B) less absorption coefficient

(C) less scattering

(D) refraction

Question: 5

Who had showed that the electric and magnetic waves are equal in vacuum?

(A) Albert Einstein

(B) Werner Heisenberg

(C) Isaac Newton

(D) James Clerk Maxwell