41. What is the phenomenon of bouncing back of light in the same medium on striking the surface of any object known as?
What is the phenomenon of bouncing back of light in the same medium on striking the surface of any object known as?
[A] Refraction
[B] Absorption
[C] Reflection
[D] Diffusion
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Correct Answer: C [Reflection]
Notes:
Reflection of light is the phenomenon of bouncing back of light in the same medium on striking the surface of any object.
42.What is the value of permittivity of free space?
[A] 8.854 × 10–10 C2 N–1 m–2
[B] 8.854 × 10–11 C2 N–1 m–2
[C] 8.854 × 10–12 C2 N–1 m–2
[D] 8.854 × 10–13 C2 N–1 m–2
Hide Answer
Correct Answer: C [8.854 × 10–12 C2 N–1 m–2 ]
Notes:
The value of permittivity of free space (ε0) in SI units is 8.854 × 10–12 C2 N–1 m–2.
43.What is the direction of current through electrolyte in a galvanic cell?
[A] flows from cathode to anode
[B] flows from anode to cathode
[C] flows in both direction
[D] None of the above
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Correct Answer: B [flows from anode to cathode]
Notes:
Current flows from anode to cathode through electrolyte.
44.Which of the following is NOT correct about the force of interaction between two poles of a magnet, as per coulomb’s law?
[A] directly proportional to the product of the pole strength
[B] directly proportional to the square of the distance r between the poles
[C] Both a and b
[D] None of the above
Hide Answer
Correct Answer: B [directly proportional to the square of the distance r between the poles]
Notes:
As per coulomb’s law, the force of interaction between two poles of a magnet is directly proportional to the product of the pole strength and inversely proportional to the square of the distance r between them.
45.Which of the following element has an isotope named as Tritium?
[A] Helium
[B] Carbon
[C] Titanium
[D] Hydrogen
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Correct Answer: D [Hydrogen]
Notes:
The three most stable isotopes of hydrogen: protium, deuterium, and tritium.
46.What is the energy equivalence of one atomic mass unit?
[A] 93.125 eV
[B] 931.25 eV
[C] 9.31 eV
[D] 0.93125 eV
Hide Answer
Correct Answer: B [931.25 eV]
Notes:
1 a.m.u. represents the average mass of a nucleon and 1 a.m.u. = 931.25 eV.
47.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
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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.
48.Which of the following represents the angular momentum of an electron as per Bohr’s model (h= Planck’s constant)?
[A] h/Ï€
[B] nh/2Ï€
[C] 2Ï€nh
[D] πnh
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Correct Answer: B [nh/2Ï€]
Notes:
Bohr’s postulate states that the electron revolves around the nucleus only in those orbits for which the angular momentum is some integral multiple of h/2Ï€ where h is the Planck’s constant (= 6.6 × 10–34 J s). Thus the angular momentum (L) of the orbiting electron is quantised. That is L = nh/2Ï€
49.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
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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.
50.What is the charge of a p-type semiconductor?
[A] Positive
[B] Negative
[C] Neutral
[D] None of the above
Hide Answer
Correct Answer: C [Neutral]
Notes:
The number of free electrons is exactly equal to the total number of holes and positively charged ions and a semiconductor, whether intrinsic or doped, is electrically neutral