Join WhatsApp ChannelDaily MCQs & Exam Updates

PPSC MCQs

Punjab Public Service Commission — Complete MCQ Bank

86 Questions
Exam Preparation Guide

How to prepare for PPSC

PPSC examinations recruit candidates for Punjab government departments and commonly test general knowledge, current affairs, English and post-related subjects.

Punjab AffairsGeneral KnowledgeCurrent AffairsEnglish
Give special attention to Punjab geography, history and administration alongside the advertised post’s specialist syllabus.
Start PracticingTake a Mock Test
PPSC preparation illustration
All Subjects Biology Chemistry Computer Science Current Affairs English Everyday Science General Knowledge Islamic Studies Mathematics Pakistan Studies Physics
31
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 — 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
32
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 — 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
33
Physics Medium

Which law explains why rockets can propel themselves in space?

  • ANewton's First Law
  • BNewton's Third Law
  • CBernoulli's Principle
  • DNewton's Second Law
Permalink
Correct Answer: Option B — Newton's Third Law
Explanation: Rockets work on Newton's Third Law as gases expelled backward at high speed produce an equal and opposite forward thrust allowing propulsion even in the vacuum of space.
Submitted by: PaperMCQs
34
Physics Medium

What is the principle of conservation of momentum?

  • AMomentum increases with velocity only
  • BTotal momentum of an isolated system remains constant
  • CMomentum equals mass times acceleration
  • DMomentum decreases with time
Permalink
Correct Answer: Option B — Total momentum of an isolated system remains constant
Explanation: The principle of conservation of momentum states that the total momentum of an isolated system remains constant provided no external forces act on it.
Submitted by: PaperMCQs
35
Physics Medium

Which principle explains why an aircraft wing generates lift?

  • APascal's principle
  • BBernoulli's principle
  • CArchimedes' principle
  • DNewton's first law only
Permalink
Correct Answer: Option B — Bernoulli's principle
Explanation: Bernoulli's principle explains that faster moving air over the curved upper wing surface has lower pressure than the slower air beneath creating a net upward lift force.
Submitted by: PaperMCQs
36
Physics Medium

What does a transformer do to alternating current?

  • AChanges the voltage of AC
  • BConverts AC to DC
  • CConverts DC to AC
  • DChanges the frequency of AC
Permalink
Correct Answer: Option A — Changes the voltage of AC
Explanation: A transformer changes the voltage of alternating current using electromagnetic induction between primary and secondary coils stepping voltage up or down depending on the turns ratio.
Submitted by: PaperMCQs
37
Physics Medium

Which formula correctly represents the relationship between frequency wavelength and speed of a wave?

  • Av equals f divided by wavelength
  • Bv equals wavelength divided by f
  • Cv equals f times wavelength
  • Df equals v times wavelength
Permalink
Correct Answer: Option C — v equals f times wavelength
Explanation: The wave equation states that wave speed v equals frequency f multiplied by wavelength lambda showing that for a given medium as frequency increases wavelength decreases proportionally.
Submitted by: PaperMCQs
38
Physics Medium

Which phenomenon explains why the sky appears blue?

  • AScattering of blue light by atmospheric molecules
  • BReflection of ocean colour
  • CAbsorption of blue light by clouds
  • DRefraction through ice crystals
Permalink
Correct Answer: Option A — Scattering of blue light by atmospheric molecules
Explanation: The sky appears blue due to Rayleigh scattering where shorter blue wavelengths of sunlight are scattered more strongly by atmospheric gas molecules than longer wavelength red light.
Submitted by: PaperMCQs
39
Physics Medium

What is the half-life of a radioactive substance?

  • ATime for the substance to completely decay
  • BTime for the radiation to halve in intensity only
  • CTime for half the nuclei to decay
  • DTime for temperature to reduce by half
Permalink
Correct Answer: Option C — Time for half the nuclei to decay
Explanation: Half-life is the time required for half of the radioactive nuclei in a sample to decay and it is a constant characteristic value specific to each radioactive isotope.
Submitted by: PaperMCQs
40
Physics Medium

Which type of radiation consists of helium nuclei emitted from an unstable nucleus?

  • AAlpha radiation
  • BBeta radiation
  • CGamma radiation
  • DNeutron radiation
Permalink
Correct Answer: Option A — Alpha radiation
Explanation: Alpha radiation consists of particles identical to helium-4 nuclei containing two protons and two neutrons emitted from heavy unstable nuclei during radioactive decay.
Submitted by: PaperMCQs
Other Exams
CSS MCQs PMS MCQs FPSC MCQs PPSC MCQs NTS MCQs
Mock Tests
Quick Test (20 Q) Full Mock (60 Q)