The first law of thermodynamics is a statement of –
(A) Conservation of mass
(B) Conservation of energy
(C) Conservation of heat
(D) Conservation of temperature
Answer: (B)
Alpha particles consist of –
(A) 2 protons only
(B) 2 electrons
(C) 2 protons and 2 neutrons
(D) 4 protons
Answer: (C)
The unit of force in CGS system is –
(A) Newton
(B) Dyne
(C) Erg
(D) Joule
Answer: (B)
Doppler effect is a change in –
(A) Frequency due to relative motion
(B) Wavelength due to temperature
(C) Velocity due to altitude
(D) Amplitude due to pressure
Answer: (A)
A vapor changes to liquid by –
(A) Boiling
(B) Condensation
(C) Fusion
(D) Sublimation
Answer: (B)
The power factor of a purely inductive circuit is –
(A) 0
(B) 1
(C) 0.5
(D) ∞
Answer: (A)
Ultraviolet rays are harmful because they –
(A) Carry low energy
(B) Have short wavelength
(C) Ionize atoms
(D) Are invisible
Answer: (C)
A body is said to be in equilibrium when –
(A) Acceleration is zero
(B) Net force is zero
(C) Velocity is zero
(D) Mass is zero
Answer: (B)
The time taken for one complete oscillation is called –
(A) Frequency
(B) Period
(C) Amplitude
(D) Phase
Answer: (B)
Laws of reflection hold true for –
(A) Plane surfaces
(B) Curved surfaces
(C) All reflecting surfaces
(D) Polished surfaces only
Answer: (C)
Thermodynamic processes which occur at constant temperature are –
(A) Isochoric
(B) Isobaric
(C) Isothermal
(D) Adiabatic
Answer: (C)
Electric lines of force never –
(A) Intersect
(B) Curve
(C) Radiate
(D) Bend
Answer: (A)
The mass of Earth affects –
(A) Gravity only
(B) All forces
(C) Only time
(D) Temperature
Answer: (A)
The metal with highest electrical conductivity is –
(A) Copper
(B) Gold
(C) Silver
(D) Aluminum
Answer: (C)
A nuclear fusion reaction occurs in –
(A) Sun
(B) Earth’s core
(C) Thermometers
(D) Nuclear reactors
Answer: (A)
The number of neutrons in deuterium is –
(A) 0
(B) 1
(C) 2
(D) 3
Answer: (B)
The magnetic field around a straight current-carrying wire is –
(A) Radial
(B) Circular
(C) Linear
(D) Constant
Answer: (B)
The SI unit of dynamic viscosity is –
(A) Pa·s
(B) N·m
(C) kg/m
(D) Poise
Answer: (A)
A circuit breaker works on the principle of –
(A) Overheating
(B) Electromagnetism
(C) Heat expansion
(D) Lenz’s law
Answer: (B)
The function of fuse in electrical circuit is to –
(A) Increase voltage
(B) Stop sparks
(C) Break circuit when overloaded
(D) Reduce resistance
Answer: (C)
SI unit of electric flux is –
(A) Nm²/C
(B) V/m
(C) C/m²
(D) A/m²
Answer: (A)
X-rays are used in –
(A) Sonography
(B) Cancer therapy
(C) Microscopy
(D) Radiography
Answer: (D)
The unit of Planck’s constant is –
(A) J·s
(B) N·m²
(C) eV·m
(D) C·s
Answer: (A)
SI unit of entropy is –
(A) J
(B) J/K
(C) W/K
(D) J·mol⁻¹·K⁻¹
Answer: (B)
When a liquid is heated, its surface tension –
(A) Increases
(B) Decreases
(C) Remains same
(D) First increases then decreases
Answer: (B)
Wien’s displacement law relates –
(A) Frequency and intensity
(B) Temperature and peak wavelength
(C) Energy and frequency
(D) Velocity and color
Answer: (B)
A transformer core is laminated to –
(A) Reduce weight
(B) Reduce eddy current loss
(C) Increase strength
(D) Reduce voltage
Answer: (B)
The focal length of a mirror is –
(A) Distance from pole to center
(B) Half of radius of curvature
(C) Twice the radius
(D) Always positive
Answer: (B)
The unit of energy in CGS system is –
(A) Erg
(B) Dyne
(C) Calorie
(D) Joule
Answer: (A)
The device used to split light into spectrum is –
(A) Prism
(B) Lens
(C) Mirror
(D) Glass slab
Answer: (A)
A body floats in a fluid if –
(A) Its weight > buoyant force
(B) Its density > fluid density
(C) Its weight = buoyant force
(D) It is weightless
Answer: (C)
The magnetism in soft iron is –
(A) Permanent
(B) Temporary
(C) Weak
(D) Natural
Answer: (B)
A magnetic field can deflect –
(A) Stationary charge
(B) Moving charge
(C) Neutrons
(D) Photons
Answer: (B)
The electrical conductivity of a superconductor is –
(A) Zero
(B) Infinite
(C) Low
(D) Variable
Answer: (B)
The area under a force–displacement graph gives –
(A) Power
(B) Acceleration
(C) Work
(D) Energy
Answer: (C)
The mirror used in streetlights is –
(A) Plane
(B) Convex
(C) Concave
(D) Cylindrical
Answer: (B)
The law of conservation of angular momentum applies to –
(A) Linear motion
(B) Rotating bodies
(C) Fluids
(D) Static bodies
Answer: (B)
Compton effect is associated with –
(A) Light as a wave
(B) Light as a particle
(C) Refraction
(D) Diffraction
Answer: (B)
A ball in free fall reaches terminal velocity when –
(A) Acceleration = 0
(B) Velocity = 0
(C) Air resistance = weight
(D) Air resistance = 0
Answer: (C)
Acceleration is a –
(A) Scalar
(B) Vector
(C) Constant
(D) Unitless
Answer: (B)
Ultrasonic waves have frequency –
(A) < 20 Hz
(B) 20–20,000 Hz
(C) > 20,000 Hz
(D) 2–200 Hz
Answer: (C)
LEDs are preferred over bulbs because –
(A) Higher current
(B) Less voltage
(C) More power
(D) Energy efficiency
Answer: (D)
Light shows dual nature based on –
(A) Interference
(B) Reflection
(C) Photoelectric effect and diffraction
(D) Scattering
Answer: (C)
Bernoulli’s principle is used in –
(A) Venturimeter
(B) Steam engine
(C) Heat pump
(D) Transformer
Answer: (A)
The reason for mirage is –
(A) Reflection
(B) Refraction
(C) Total internal reflection
(D) Absorption
Answer: (C)
Energy in an AC circuit is measured in –
(A) kVA
(B) kWh
(C) Joules
(D) kVAR
Answer: (B)
A fuse wire is made of –
(A) Low resistance alloy
(B) High resistance alloy
(C) Copper
(D) Iron
Answer: (B)
A refrigerant has –
(A) High boiling point
(B) Low boiling point
(C) High specific heat
(D) High viscosity
Answer: (B)
The unit of magnetic flux is –
(A) Tesla
(B) Weber
(C) Henry
(D) Gauss
Answer: (B)
A geostationary satellite completes one revolution in –
(A) 12 hours
(B) 6 hours
(C) 24 hours
(D) 48 hours
Answer: (C)