A. oxygen and hydrogen
B. oxygen, hydrogen, acetylene and nitrogen
C. oxygen, acetylene and argon
D. oxygen and acetylene
✅ The correct answer is option D.
General Science MCQs
42. From which mineral is radium obtained?
A. Rutile
B. Haematite
C. Limestone
D. Pitchblende
✅ The correct answer is option D.
43. What is the wavelength of visible spectrum?
A. 8500 – 9800 angstrom
B. 7800 – 8000 angstrom
C. 3900 – 7600 angstrom
D. 1300 – 3000 angstrom
✅ The correct answer is option C.
44. Mesons are found in
A. Laser beam
B. X-rays
C. Gamma rays
D. Cosmic rays
✅ The correct answer is option D.
45. The main constituents of pearls are
A. calcium oxide and ammonium chloride
B. calcium carbonate and magnesium carbonate
C. aragonite and conchiolin
D. ammonium sulphate and sodium carbonate
✅ The correct answer is option B.
46. According to Avogadro’s Hypothesis, the smallest particle of an element or a compound, that can exist independently, is called ____ .
A. a molecule
B. a cation
C. an anion
D. an atom
✅ The correct answer is option A.
47. ‘No two electrons in an atom can have the same set of four quantum numbers’ is
A. Newton’s law
B. Bohr’s law
C. Aufbau principle
D. Pauli’s exclusion principle
✅ The correct answer is option D.
48. Which of the following is not an isotope of hydrogen?
A. Tritium
B. Deuterium
C. Protium
D. Yttrium
✅ The correct answer is option D.
http://en.wikipedia.org/wiki/Isotopes_of_hydrogen
http://en.wikipedia.org/wiki/Isotopes_of_hydrogen
49. Diamond is an allotropic form of
A. germanium
B. carbon
C. silicon
D. sulphur
✅ The correct answer is option B.
50. Light year is a measurement of
A. speed of aeroplanes
B. speed of light
C. Stellar distances
D. speed of rockets
✅ The correct answer is option C.