The amount of energy radiated by a black body is governed by –
(A) Wien’s Law
(B) Planck’s Law
(C) Stefan–Boltzmann Law
(D) Newton’s Law
Answer: (C)
Electroplating is based on –
(A) Magnetic induction
(B) Electrolysis
(C) Ionization
(D) Conductance
Answer: (B)
The resistance of a metal wire increases with –
(A) Decrease in temperature
(B) Increase in temperature
(C) Increase in humidity
(D) Increase in current
Answer: (B)
A ball dropped from a height has –
(A) Constant acceleration
(B) Constant velocity
(C) Increasing mass
(D) Constant kinetic energy
Answer: (A)
The device that converts AC to DC is called –
(A) Amplifier
(B) Rectifier
(C) Transistor
(D) Oscillator
Answer: (B)
The intensity of gravitational field at Earth’s surface is –
(A) 1 N/kg
(B) 4.9 N/kg
(C) 9.8 N/kg
(D) 10 N/kg
Answer: (C)
SI unit of modulus of elasticity is –
(A) N
(B) N/m
(C) Pascal
(D) m/s²
Answer: (C)
Solar cells are made of –
(A) Silicon
(B) Carbon
(C) Copper
(D) Graphite
Answer: (A)
The speed of light in diamond is –
(A) More than in air
(B) Equal to that in vacuum
(C) Less than in water
(D) Less than in air
Answer: (D)
A voltmeter is always connected in –
(A) Series
(B) Parallel
(C) Ground
(D) Diagonal
Answer: (B)
A battery of 12 V means –
(A) Charge flows at 12 J
(B) 12 C flows per second
(C) 12 J of work done per coulomb
(D) Resistance is 12 Ohm
Answer: (C)
The sound speed in air increases with –
(A) Decrease in temperature
(B) Increase in humidity
(C) Decrease in humidity
(D) Higher pressure
Answer: (B)
Photon is a particle of –
(A) Electron
(B) Neutron
(C) Light
(D) Proton
Answer: (C)
The product of force and displacement is –
(A) Power
(B) Work
(C) Energy
(D) Torque
Answer: (B)
SI unit of strain is –
(A) m/m
(B) m²
(C) Unitless
(D) Pascal
Answer: (C)
A pendulum clock goes slow at –
(A) Equator
(B) Pole
(C) Higher altitude
(D) Sea level
Answer: (C)
Brownian motion proves –
(A) Electrons exist
(B) Kinetic theory of matter
(C) Atomic structure
(D) Chemical bonding
Answer: (B)
Capacitance increases when –
(A) Area increases
(B) Distance decreases
(C) Dielectric constant increases
(D) All of the above
Answer: (D)
The SI unit of torque is –
(A) Nm
(B) N/m
(C) J
(D) kg·m²/s²
Answer: (A)
A concave mirror forms a virtual image when object is –
(A) At center of curvature
(B) Between pole and focus
(C) Beyond focus
(D) At infinity
Answer: (B)
Rutherford’s experiment proved –
(A) Atom is indivisible
(B) Atom has dense nucleus
(C) Atom has electrons only
(D) Atom is solid sphere
Answer: (B)
The unit of thermal conductivity is –
(A) W/m·K
(B) W/K
(C) J/m·K
(D) Cal/cm·K
Answer: (A)
A newton-second is the unit of –
(A) Force
(B) Momentum
(C) Work
(D) Power
Answer: (B)
Hydrometer works on –
(A) Buoyancy
(B) Pressure
(C) Capillary action
(D) Diffusion
Answer: (A)
The transmission of heat through solids occurs by –
(A) Conduction
(B) Convection
(C) Radiation
(D) Emission
Answer: (A)
A mirror image is laterally inverted due to –
(A) Refraction
(B) Angle of incidence
(C) Plane mirror’s reflection
(D) Curvature
Answer: (C)
The resistance of a conductor is directly proportional to –
(A) Cross-sectional area
(B) Square of length
(C) Length
(D) Voltage
Answer: (C)
A hot iron ball emits radiation due to –
(A) Conduction
(B) Black body radiation
(C) Nuclear fusion
(D) Refraction
Answer: (B)
Refrigerators work on the principle of –
(A) Joule effect
(B) Thermodynamics
(C) Electromagnetic induction
(D) Thermal expansion
Answer: (B)
The voltage across a resistor in a circuit depends on –
(A) Current
(B) Resistance
(C) Ohm’s Law
(D) All of the above
Answer: (D)
The color of the sun appears red at sunset due to –
(A) Refraction
(B) Scattering of shorter wavelengths
(C) Polarization
(D) Dispersion
Answer: (B)
A compressive stress acts to –
(A) Stretch
(B) Expand
(C) Shorten
(D) Oscillate
Answer: (C)
The SI unit of angular acceleration is –
(A) rad/s²
(B) m/s²
(C) rpm
(D) rad/s
Answer: (A)
Electric potential is –
(A) Energy per unit charge
(B) Force per unit charge
(C) Charge per unit energy
(D) Work per unit time
Answer: (A)
The total internal reflection occurs when –
(A) Light goes from rarer to denser
(B) Light goes from denser to rarer
(C) Light goes from vacuum to air
(D) Always at 90°
Answer: (B)
The first law of motion is also called –
(A) Law of force
(B) Law of inertia
(C) Law of gravitation
(D) Law of work
Answer: (B)
The resistance of an ideal voltmeter is –
(A) Zero
(B) One
(C) Infinite
(D) Very low
Answer: (C)
The threshold frequency in photoelectric effect is –
(A) Minimum energy to release electron
(B) Minimum frequency of light
(C) Maximum voltage
(D) Ionization limit
Answer: (B)
A rocket launches due to –
(A) Momentum conservation
(B) Gravity
(C) Mass change
(D) Temperature change
Answer: (A)
The working of optical fiber depends on –
(A) Refraction
(B) Diffraction
(C) Total internal reflection
(D) Dispersion
Answer: (C)
Heat capacity =
(A) Mass × specific heat
(B) Specific heat / mass
(C) Work × temperature
(D) Pressure × volume
Answer: (A)
A neutral atom has –
(A) Equal protons and neutrons
(B) Equal electrons and neutrons
(C) Equal protons and electrons
(D) No charge
Answer: (C)
The center of gravity is the point where –
(A) Mass is maximum
(B) Weight acts
(C) Area is minimum
(D) No force acts
Answer: (B)
Escape velocity is –
(A) Same on all planets
(B) Less on Moon
(C) Equal to orbital velocity
(D) Zero in space
Answer: (B)
The charge on neutron is –
(A) +1
(B) –1
(C) 0
(D) +2
Answer: (C)
Temperature of the sun’s surface is approx –
(A) 6000°C
(B) 500°C
(C) 1000°C
(D) 10000°C
Answer: (A)
A measuring cylinder is used to –
(A) Heat liquids
(B) Mix solutions
(C) Measure volume
(D) Weigh solids
Answer: (C)
A wave with frequency below 20 Hz is –
(A) Audible
(B) Ultrasonic
(C) Infrasonic
(D) Harmonic
Answer: (C)
A microscope gives –
(A) Real, inverted, magnified image
(B) Virtual, upright
(C) Enlarged only
(D) Diminished, real
Answer: (A)
The SI unit of entropy is –
(A) J/K
(B) W/K
(C) N/m
(D) Cal/mol
Answer: (A)