Join WhatsApp ChannelDaily MCQs & Exam Updates

CSS MCQs

Civil Superior Services β€” Complete MCQ Bank

899 Questions
Exam Preparation Guide

How to prepare for CSS

CSS is Pakistan’s premier federal competitive examination. Strong preparation requires conceptual clarity, broad general knowledge and consistent practice across compulsory and optional areas.

Pakistan AffairsCurrent AffairsEnglishEveryday Science
Combine daily MCQ practice with analytical reading, vocabulary building and regular revision of national and international affairs.
CSS preparation illustration
111
Physics Medium

Which scale of temperature is used in thermodynamic calculations and starts at absolute zero?

  • AKelvin
  • BCelsius
  • CFahrenheit
  • DRankine
Permalink
Correct Answer: Option A β€” Kelvin
Explanation: The Kelvin scale is the SI thermodynamic temperature scale starting at absolute zero and used in all scientific thermodynamic calculations because it has no negative values.
Submitted by: PaperMCQs
112
Physics Medium

What is absolute zero temperature in degrees Celsius?

  • A0 degrees Celsius
  • Bminus 100 degrees Celsius
  • Cminus 273 degrees Celsius
  • Dminus 373 degrees Celsius
Permalink
Correct Answer: Option C β€” minus 273 degrees Celsius
Explanation: Absolute zero is minus 273.15 degrees Celsius or 0 Kelvin the theoretical lowest temperature at which particles have minimum thermal motion.
Submitted by: PaperMCQs
113
Physics Hard

What is the unit of luminous intensity in the SI system?

  • ALux
  • BLumen
  • CWatt
  • DCandela
Permalink
Correct Answer: Option D β€” Candela
Explanation: The Candela is the SI base unit of luminous intensity representing the power emitted by a light source in a particular direction per unit solid angle.
Submitted by: PaperMCQs
114
Physics Hard

What is polarisation of light?

  • ASplitting light into its spectrum
  • BRestriction of light vibrations to a single plane
  • CBending of light around obstacles
  • DTotal reflection of light
Permalink
Correct Answer: Option B β€” Restriction of light vibrations to a single plane
Explanation: Polarisation restricts the transverse vibrations of light to a single plane demonstrating that light is a transverse wave and is used in polaroid sunglasses and LCD screens.
Submitted by: PaperMCQs
115
Physics Medium

Which experiment demonstrated that light behaves as a wave by producing an interference pattern?

  • AYoung's double slit experiment
  • BRutherford's gold foil experiment
  • CMillikan's oil drop experiment
  • DCompton scattering experiment
Permalink
Correct Answer: Option A β€” Young's double slit experiment
Explanation: Young's double slit experiment demonstrated light's wave nature by producing alternating bright and dark fringes on a screen when coherent light passed through two closely spaced slits.
Submitted by: PaperMCQs
116
Physics Medium

What is the phenomenon where two waves superpose to produce regions of maximum and minimum intensity?

  • AInterference
  • BDiffraction
  • CRefraction
  • DPolarisation
Permalink
Correct Answer: Option A β€” Interference
Explanation: Interference occurs when two coherent waves superpose to produce alternating regions of constructive interference maximum intensity and destructive interference minimum intensity.
Submitted by: PaperMCQs
117
Physics Hard

Which device uses the piezoelectric effect to produce ultrasonic waves?

  • ALoudspeaker
  • BMicrophone
  • CElectric motor
  • DUltrasonic transducer
Permalink
Correct Answer: Option D β€” Ultrasonic transducer
Explanation: An ultrasonic transducer uses the piezoelectric effect where certain crystals generate mechanical vibrations when an electric voltage is applied producing high frequency sound waves.
Submitted by: PaperMCQs
118
Physics Medium

What is simple harmonic motion?

  • AMotion in a circle at constant speed
  • BOscillatory motion where restoring force is proportional to displacement
  • CUniform linear motion
  • DRandom motion under multiple forces
Permalink
Correct Answer: Option B β€” Oscillatory motion where restoring force is proportional to displacement
Explanation: Simple harmonic motion is a type of oscillatory motion where the restoring force is directly proportional to the displacement from equilibrium and directed toward the equilibrium position.
Submitted by: PaperMCQs
119
Physics Hard

Which phenomenon causes a spinning top to precess rather than fall over immediately?

  • AConservation of energy
  • BMagnetic force
  • CGyroscopic effect
  • DCentripetal force only
Permalink
Correct Answer: Option C β€” Gyroscopic effect
Explanation: The gyroscopic effect causes a spinning top to precess slowly around a vertical axis rather than falling over because its angular momentum resists changes to its orientation.
Submitted by: PaperMCQs
120
Physics Hard

What is the escape velocity from Earth's surface approximately?

  • A11.2 km/s
  • B7.9 km/s
  • C5.5 km/s
  • D15 km/s
Permalink
Correct Answer: Option A β€” 11.2 km/s
Explanation: The escape velocity from Earth's surface is approximately 11.2 kilometres per second the minimum speed needed for an object to escape Earth's gravitational pull without further propulsion.
Submitted by: PaperMCQs