Physics MCQs – Set 14: High-Level Questions for UPSC/PCS Exam Prep

  1. A light ray entering glass from air bends –
    (A) Away from the normal
    (B) Toward the normal
    (C) Does not bend
    (D) Reflects back
    Answer: (B)
  2. The resonance condition in an LCR circuit results in –
    (A) Zero current
    (B) Infinite resistance
    (C) Maximum current
    (D) No voltage
    Answer: (C)
  3. 1 horsepower is equal to –
    (A) 746 watts
    (B) 1 kilowatt
    (C) 550 watts
    (D) 500 watts
    Answer: (A)
  4. Momentum is conserved in –
    (A) Inelastic collisions only
    (B) Elastic collisions only
    (C) All types of collisions
    (D) Explosions only
    Answer: (C)
  5. Voltage across a capacitor in a DC circuit –
    (A) Increases indefinitely
    (B) Drops to zero
    (C) Builds up then stays constant
    (D) Oscillates
    Answer: (C)
  6. A tuning fork is used to produce –
    (A) Loud sounds
    (B) Light
    (C) Musical note of known frequency
    (D) Electrical signals
    Answer: (C)
  7. The wavelength of UV rays is –
    (A) 10–400 nm
    (B) 400–700 nm
    (C) 1–10 nm
    (D) 700–1000 nm
    Answer: (A)
  8. The SI unit of work done is –
    (A) Newton
    (B) Joule
    (C) Watt
    (D) Erg
    Answer: (B)
  9. A body of mass m moving at speed v has kinetic energy –
    (A) mv²
    (B) ½mv
    (C) ½mv²
    (D) m²v
    Answer: (C)
  10. A vibration that fades over time is called –
    (A) Simple harmonic motion
    (B) Periodic motion
    (C) Damped vibration
    (D) Natural vibration
    Answer: (C)
  11. Resistance of a conductor increases with –
    (A) Decrease in length
    (B) Increase in temperature
    (C) Increase in area
    (D) Better conductor
    Answer: (B)
  12. SI unit of heat capacity is –
    (A) J/kg·K
    (B) J/K
    (C) Cal/g
    (D) K
    Answer: (B)
  13. The refractive index of vacuum is –
    (A) 0
    (B) 1
    (C) Infinite
    (D) Varies
    Answer: (B)
  14. A concave mirror is also called –
    (A) Diverging mirror
    (B) Plane mirror
    (C) Converging mirror
    (D) Flat mirror
    Answer: (C)
  15. Specific gravity is defined as –
    (A) Density / mass
    (B) Density of substance / density of water
    (C) Mass / density
    (D) Volume / weight
    Answer: (B)
  16. The principle of conservation of energy states that –
    (A) Energy is always lost
    (B) Energy can’t be transformed
    (C) Total energy remains constant
    (D) Work equals force
    Answer: (C)
  17. The displacement in a circular path is –
    (A) Circumference
    (B) Zero
    (C) Radius
    (D) Arc length
    Answer: (B)
  18. A photo diode operates under –
    (A) Forward bias
    (B) Reverse bias
    (C) Zero bias
    (D) AC supply
    Answer: (B)
  19. The power of an appliance is calculated by –
    (A) Voltage × resistance
    (B) Voltage / resistance
    (C) Voltage × current
    (D) Current / voltage
    Answer: (C)
  20. A liquid drop forms a sphere due to –
    (A) Gravity
    (B) Cohesion
    (C) Surface tension
    (D) Adhesion
    Answer: (C)
  21. Ohm’s Law holds good for –
    (A) Vacuum
    (B) All devices
    (C) Metallic conductors
    (D) Diodes
    Answer: (C)
  22. A current of 2 A flowing for 10 seconds transfers –
    (A) 2 C
    (B) 10 C
    (C) 20 C
    (D) 5 C
    Answer: (C)
  23. The velocity of sound in steel is approx –
    (A) 340 m/s
    (B) 1000 m/s
    (C) 5000 m/s
    (D) 10000 m/s
    Answer: (C)
  24. The acceleration of a body at rest is –
    (A) 0
    (B) 9.8 m/s²
    (C) Infinite
    (D) Variable
    Answer: (A)
  25. The center of mass of a uniform ring lies –
    (A) At the center
    (B) On the circumference
    (C) Outside the ring
    (D) Varies
    Answer: (A)
  26. Inertia is the property that –
    (A) Opposes acceleration
    (B) Resists change in motion
    (C) Produces motion
    (D) Changes direction
    Answer: (B)
  27. The amount of charge in 1 mole of electrons is –
    (A) 1 C
    (B) 9.8 C
    (C) 96,500 C
    (D) 6.022 × 10²³ C
    Answer: (C)
  28. A sonometer measures –
    (A) Weight
    (B) Sound intensity
    (C) Frequency
    (D) Acceleration
    Answer: (C)
  29. The energy stored in a spring is –
    (A) mgh
    (B) ½kx²
    (C) kx
    (D) ½mv²
    Answer: (B)
  30. A fuse is rated by –
    (A) Voltage
    (B) Current
    (C) Resistance
    (D) Wattage
    Answer: (B)
  31. Dispersion occurs due to –
    (A) Change in speed with frequency
    (B) Reflection
    (C) Interference
    (D) Polarization
    Answer: (A)
  32. Thermal equilibrium implies –
    (A) No heat exchange
    (B) Same pressure
    (C) Equal volume
    (D) Same density
    Answer: (A)
  33. The power output of a machine is 100 W. In 5 sec it does –
    (A) 5 J
    (B) 20 J
    (C) 500 J
    (D) 1000 J
    Answer: (C)
  34. Pressure cooker works faster because –
    (A) More steam escapes
    (B) Temperature rises with pressure
    (C) More oxygen is present
    (D) Less water is used
    Answer: (B)
  35. Spherical aberration occurs in –
    (A) Mirrors only
    (B) Lenses only
    (C) Both lenses and mirrors
    (D) Prisms
    Answer: (C)
  36. Red light travels fastest in –
    (A) Water
    (B) Glass
    (C) Air
    (D) Vacuum
    Answer: (D)
  37. A liquid exhibits surface tension because –
    (A) Molecules attract each other
    (B) Molecules repel each other
    (C) Liquids expand
    (D) Density is high
    Answer: (A)
  38. The magnetic field inside a long solenoid is –
    (A) Non-uniform
    (B) Zero
    (C) Constant
    (D) Variable
    Answer: (C)
  39. Escape velocity on Earth is about –
    (A) 7.9 km/s
    (B) 9.8 m/s
    (C) 11.2 km/s
    (D) 20 km/s
    Answer: (C)
  40. The term “light” in physics refers to –
    (A) Infrared rays
    (B) Electromagnetic radiation visible to eye
    (C) Ultraviolet rays
    (D) White light only
    Answer: (B)
  41. Lightning conductor protects buildings by –
    (A) Absorbing charges
    (B) Grounding excess charge
    (C) Repelling clouds
    (D) Ionizing air
    Answer: (B)
  42. The lens used in magnifying glass is –
    (A) Concave
    (B) Convex
    (C) Plane
    (D) Plano-concave
    Answer: (B)
  43. Inertia of motion explains –
    (A) A moving object continues to move
    (B) Resting object remains at rest
    (C) Object resists acceleration
    (D) Object attracts other objects
    Answer: (A)
  44. Energy stored in capacitor is measured in –
    (A) Joule
    (B) Volt
    (C) Ampere
    (D) Watt
    Answer: (A)
  45. A transistor is used in –
    (A) Rectification
    (B) Amplification
    (C) Energy storage
    (D) Circuit breaking
    Answer: (B)
  46. Refraction is the bending of light when it –
    (A) Reflects
    (B) Passes from one medium to another
    (C) Disperses
    (D) Scatters
    Answer: (B)
  47. The angle of incidence = angle of reflection is explained by –
    (A) Newton’s Laws
    (B) Huygens’ Principle
    (C) Law of reflection
    (D) Fermat’s Principle
    Answer: (C)
  48. A capacitor blocks
    (A) DC
    (B) AC
    (C) Both
    (D) None
    Answer: (A)
  49. Black holes are detected through –
    (A) Emitted light
    (B) Reflected waves
    (C) Gravitational waves and X-rays
    (D) Electric field
    Answer: (C)
  50. The size of nucleus is in the order of –
    (A) 10⁻⁶ m
    (B) 10⁻⁹ m
    (C) 10⁻¹⁰ m
    (D) 10⁻¹⁴ m
    Answer: (D)

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