Practice Physics MCQ Questions 26–43 out of 43. Free quiz with answers and explanations for UPSC, SSC, Railway exam preparation. Strengthen your general science fundamentals with our technical Physics GK quiz. Practice high-frequency multiple-choice questions on mechanics, thermodynamics, light, optics, electricity, magnetism, and modern atomic physics tailored perfectly to meet the syllabus requirements of SSC, RRB NTPC, and NDA.
Myopia requires a diverging (concave) lens to spread incoming light rays so that they focus perfectly on the retina, not in front of it. [Memory Trick: When objects are close, I 'Cave' in my focus = corrected by 'Concave' lenses.]
Iridescence is caused by light reflecting off both the outer and inner boundaries of a microscopic thin film, creating constructive and destructive wave interference. [Memory Trick: Waves 'interfere' with each other at the bubble's edge to paint a rainbow.]
Dutch physicist Christiaan Huygens proposed that light traveled as wave fronts, which explained reflection and refraction using the Huygens' Principle. [Memory Trick: 'Huygens' waves say 'Hi' from every wavefront.]
Newton's First Law states that an object remains at rest or in uniform motion unless acted upon by an external net force. This resistance to change is Inertia. [Memory Trick: 'First' response of any lazy object is to say 'No, I won't move!' = Inertia.]
Luminous intensity is measured in Candela (symbol: cd), which is approximately equal to the light emitted by one common historical candle. [Memory Trick: 'Candela' sounds exactly like checking light using a glowing 'candle'.]
The Doppler Effect is the change in frequency of a wave relative to an observer who is moving relative to the wave source. [Memory Trick: When the fast vehicle goes 'vroom', the sound waves get bunched up and 'Doppler-shift' past you.]
Cadmium and Boron have high neutron capturing capability. Control rods made of these elements can be inserted/removed to regulate the reactor's fission rate. [Memory Trick: 'Boron' rods act like a 'boring' guard that captures exciting neutrons to slow them down.]
Kepler's third law (Harmonic Law) states T^2 is proportional to a^3, relating a planet's distance from the sun to its complete year duration. [Memory Trick: Think of Kepler's formula as a game of '2 squares' and '3 cubes' (T^2 over a^3 is constant).]
MRI uses magnets supercooled to near absolute zero to align hydrogen protons in body tissue, then applies radio waves to read returning energy signals. [Memory Trick: 'M'agnetic 'R'esonance uses 'M'agnets + 'R'adio waves to image bones and tissues.]
The Barometer measures atmospheric pressure using a column of mercury. [Memory Trick: High atmospheric pressure places a heavy 'Bar' on the scale = Barometer.]
Water has a very high specific heat capacity (4.184 J/g°C), meaning it can absorb immense amounts of heat before its own temperature rises significantly. [Memory Trick: Water takes a lot of 'Capacity' to heat up, keeping the hot engine super chill!]
Hooke's Law states that the force required to stretch or compress an elastic spring is directly proportional to its displacement. [Memory Trick: Hang a metal spring on a 'Hook' (Hooke) and watch it stretch proportionally.]
When an aircraft exceeds Mach 1.0 (supersonic), it flies faster than sound, packing air pressure waves into a sharp shockwave (sonic boom). [Memory Trick: Cross the '1.0' threshold to make a boom!]
Wilhelm Röntgen accidentally discovered X-rays, taking the first internal image of his wife's hand. He named them 'X-rays' as they were unknown. [Memory Trick: Röntgen 'ran' his eyes over a skeletal hand using mysterious 'X' light rays.]
Diamond has a high refractive index (~2.42) and small critical angle (24.4 degrees). This traps light inside through total internal reflections, emerging only at flat cuts. [Memory Trick: High 'Index' captures the beam, bouncing it into a dazzling fireworks display inside.]
Brownian motion is the random jigging of particles (like pollen grains) knocked around by continuous collision with water/gas molecules. [Memory Trick: Imagine pollen grains drinking 'Brown' tea and executing a hyperactive, zigzag dance!]
To balance the momentum of the bullet moving forward, the gun experiences an equal and opposite momentum backward, keeping the system's net momentum constant. [Memory Trick: Moving forward requires a push backward to satisfy balance/conservation of 'Momentum'.]
Heisenberg's Uncertainty Principle states that the products of uncertainties in position (x) and momentum (p) of a quantum particle must be greater than or equal to h/4π. [Memory Trick: If you track down the exact 'Position' of a speedy electron, its traveling speed becomes completely 'Uncertain'!]
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