891. According to Big Bang Theory, the Universe began about ________ billion years ago.
A. 10 – 20
B. 20 – 30
C. 30 – 40
D. 40 – 50

892. Einstein’s famous equation which states that mass and energy are interchangeable is
A. E = mc2
B. E = cm2
C. M = ec2
D. M = ce2

893. The SI unit of electric current is
A. Coulomb
B. Ampere
C. Volt
D. Watt

894. The principal constituent of the atmosphere of the Earth is
A. Oxygen
B. Carbon
C. Hydrogen
D. Nitrogen

895. Which are the three primary colours?
A. White, Black, Blue
B. Red, Yellow, Blue
C. Red, Orange, Blue
D. Red, Green, Blue

896. Battery was invented by
A. Volta
B. Hero
C. Fermi
D. Maiman

897. The most abundant element in the earth’s crust is oxygen. The second most abundant element in the earth’s crust is
A. Hydrogen
B. Nitrogen
C. Brass
D. Silicon

898. The nearest planet to the Sun is
A. Mercury
B. Venus
C. Mars
D. Jupiter

899. Molecules with identical molecular formulae but with different structural formulae are called
A. Isotopes
B. Isomers
C. Electrode
D. Compound

900. Which one of the following is the main culprit in the thinning of Ozone layer in the earth’s stratosphere?
A. Carbon dioxide
B. Chlorofluorocarbon
C. Methane
D. None of these