General Science - Physics MCQs
Physics Objective (Multiple Choice) General Knowledge & General Science Questions & Answers for SSC-CGL, UPPSC, UPSC, NDA, CDS and UPSC Civil Services Prelims Examinations.
91. What are the lines joining places of zero declination known as?
[A] Isoclinic
[B] Agonic
[C] Aclinic
[D] Isogonic
Show Answer
Correct Answer: B [Agonic]
Notes:
The line joining places of zero declination is known as agonic line.
92. Which of the following element has an isotope named as Tritium?
[A] Helium
[B] Carbon
[C] Titanium
[D] Hydrogen
Show Answer
Correct Answer: D [Hydrogen]
Notes:
The three most stable isotopes of hydrogen: protium, deuterium, and tritium.
93. What is the source of energy in nuclear reactors which produce electricity?
[A] Nuclear Fission
[B] Nuclear Fusion
[C] Gamma decay
[D] None of the above
Show Answer
Correct Answer: A [Nuclear Fission]
Notes:
Nuclear Fission is the source of energy in nuclear reactors which produce electricity.
94. What do we call the energy which should be supplied to the nucleus to break it up into its constituent particles?
[A] Excitation energy
[B] Binding energy
[C] Ionisation energy
[D] None of the above
Show Answer
Correct Answer: B [Binding energy]
Notes:
Binding energy is the energy which should be supplied to the nucleus in order to break it up into its constituent particles.
95. What is meant by Atomic number of an atom?
[A] total number of protons
[B] total number of electrons in an uncharged atom
[C] Both a and b
[D] None
Show Answer
Correct Answer: C [Both a and b]
Notes:
The atomic number or proton number of a chemical element is the number of protons found in the nucleus of an atom. In an uncharged atom, the atomic number is also equal to the number of electrons.
96. Which of the following material is commonly used to make control rods in a nuclear reactor?
[A] Indium
[B] Boron
[C] Cadmium
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:
Control rods are made of boron, silver, indium and cadmium that are capable of absorbing many neutrons without themselves fissioning.
97. Which of the following metal foils was used in the Rutherford’s alpha particle scattering experiment?
[A] Copper
[B] Silver
[C] Gold
[D] Aluminium
Show Answer
Correct Answer: C [Gold]
Notes:
Rutherford directed beams of alpha particles (which are the nuclei of helium atoms and hence positively charged) at thin gold foil and noted how the alpha particles scattered from the foil.
98. Which of the following diodes is mostly commonly used as a voltage regulator?
[A] LED
[B] Varactor diode
[C] Shockley diode
[D] Zener diode
Show Answer
Correct Answer: D [Zener diode]
Notes:
Zener diode is a special purpose semiconductor diode, named after its inventor C. Zener. It is designed to operate under reverse bias in the breakdown region and used as a voltage regulator.
99. What is the output of an AND gate when both the inputs are 0?
[A] 0
[B] 1
[C] Either 0 or 1
[D] 2
Show Answer
Correct Answer: A [0]
Notes:
The AND gate is a basic digital logic gate that gives a LOW output If none or not all inputs to the AND gate are HIGH.
100. Which of these dopants is NOT used to increase the conductivity of a semi-conductor?
[A] Indium
[B] Aluminium
[C] Arsenic
[D] Boron
Show Answer
Correct Answer: B [Aluminium]
Notes:
There are two types of dopants used in doping the tetravalent Si or Ge: (i) Pentavalent (valency 5); like Arsenic (As), Antimony (Sb), Phosphorous (P), etc (ii) Trivalent (valency 3); like Indium (In), Boron (B), Aluminium (Al), etc
Advertisement
