Radioactivity was discovered by – (A) Einstein (B) Roentgen (C) Rutherford (D) Henri Becquerel Answer: (D)
A moving coil galvanometer can be converted into a voltmeter by connecting – (A) Low resistance in parallel (B) High resistance in series (C) High resistance in parallel (D) Low resistance in series Answer: (B)
The unit of electric potential is – (A) Ampere (B) Coulomb (C) Ohm (D) Volt Answer: (D)
A laser produces – (A) Incoherent light (B) Monochromatic and coherent light (C) White light (D) Infrared light only Answer: (B)
A liquid drop assumes spherical shape due to – (A) Viscosity (B) Surface tension (C) Gravity (D) Adhesion Answer: (B)
The velocity-time graph of a uniformly accelerated body is – (A) Straight line (B) Curve (C) Parabola (D) Hyperbola Answer: (A)
The focal length of a convex mirror is – (A) Positive (B) Negative (C) Zero (D) Variable Answer: (B)
A cyclotron is a device used to – (A) Split atoms (B) Accelerate charged particles (C) Produce electricity (D) Amplify signals Answer: (B)
Spectacles for hypermetropia use – (A) Concave lenses (B) Convex lenses (C) Plane mirrors (D) Cylindrical lenses Answer: (B)
Gravitational potential energy is – (A) Always positive (B) Always negative (C) Zero (D) Positive or negative Answer: (B)
The dimension of velocity is – (A) LT⁻² (B) LT⁻¹ (C) L²T (D) L²T⁻² Answer: (B)
A light ray enters a denser medium and – (A) Speeds up (B) Slows down (C) Refracts away (D) Travels straight Answer: (B)
Solar cells work on – (A) Thermoelectric effect (B) Photoelectric effect (C) Seebeck effect (D) Electromagnetic induction Answer: (B)
The capacity of a capacitor is determined by – (A) Shape of plates (B) Area and separation of plates (C) Plate material (D) External circuit Answer: (B)
A bar magnet suspended freely aligns – (A) North–South (B) East–West (C) Randomly (D) Vertically Answer: (A)
Latent heat is – (A) Heat to change temperature (B) Heat to change state (C) Heat to raise volume (D) None of these Answer: (B)
A motor converts – (A) Electrical to mechanical energy (B) Mechanical to electrical energy (C) Thermal to mechanical (D) Electrical to thermal Answer: (A)
The total resistance in a series circuit is – (A) Zero (B) Average of resistors (C) Equal to sum of individual resistances (D) Product of all resistances Answer: (C)
The optical density of a medium depends on – (A) Mass (B) Refractive index (C) Color (D) Transparency Answer: (B)
Plasma state of matter is – (A) Solid (B) Ionized gas (C) Superfluid (D) Bose-Einstein condensate Answer: (B)
The main component of natural gas is – (A) Butane (B) Methane (C) Ethane (D) Propane Answer: (B)
Pascal’s law is applied in – (A) Barometer (B) Hydraulic press (C) Manometer (D) Thermometer Answer: (B)
A graph of acceleration vs. time for uniformly accelerating object is – (A) Straight line parallel to time axis (B) Parabola (C) Curve (D) Zero Answer: (A)
The power of a lens is measured in – (A) Diopters (B) Watts (C) Lux (D) Lumen Answer: (A)
The rate of change of momentum is – (A) Energy (B) Force (C) Pressure (D) Work Answer: (B)
SI unit of luminous intensity is – (A) Lumen (B) Lux (C) Candela (D) Diopter Answer: (C)
A body moving in circle with uniform speed has – (A) Constant velocity (B) Constant acceleration (C) Constant momentum (D) Changing velocity Answer: (D)
Light is fastest in – (A) Diamond (B) Water (C) Air (D) Vacuum Answer: (D)
A good conductor has – (A) Low resistivity (B) High resistance (C) High specific heat (D) High expansion Answer: (A)
The law of conservation of momentum is derived from – (A) Newton’s 1st law (B) Newton’s 2nd law (C) Newton’s 3rd law (D) Work–Energy Theorem Answer: (C)
A gas thermometer is more accurate because – (A) Gases expand linearly (B) Gases respond quickly (C) Gases don’t freeze (D) Gases follow ideal behavior Answer: (D)
The cooling in a refrigerator is due to – (A) Loss of heat by compressor (B) Evaporation of liquid (C) Expansion of gas (D) Compression of refrigerant Answer: (B)
Mirage is observed due to – (A) Reflection (B) Total internal reflection (C) Refraction (D) Absorption Answer: (B)
The instrument to detect electric current is – (A) Voltmeter (B) Galvanometer (C) Potentiometer (D) Barometer Answer: (B)
A simple harmonic motion is – (A) Periodic and non-uniform (B) Non-periodic (C) Uniform and linear (D) Periodic and has restoring force Answer: (D)
The electrical conductivity of a semiconductor – (A) Increases with temperature (B) Decreases with temperature (C) Is constant (D) Is zero Answer: (A)
A compressed spring has – (A) Kinetic energy (B) Potential energy (C) Thermal energy (D) Electric energy Answer: (B)
A decibel is a unit of – (A) Frequency (B) Sound intensity (C) Pitch (D) Tone Answer: (B)
SI unit of angular frequency is – (A) rad/s (B) Hz (C) rpm (D) cycles/s Answer: (A)
A force acting on a body for short time is called – (A) Pressure (B) Impact (C) Impulse (D) Tension Answer: (C)
The best conductor of heat is – (A) Iron (B) Copper (C) Aluminum (D) Silver Answer: (D)
The minimum energy needed to eject an electron is – (A) Threshold frequency (B) Potential (C) Work function (D) Voltage Answer: (C)
A liquid boils when – (A) Surface vaporizes (B) Temperature falls (C) Vapor pressure equals atmospheric pressure (D) Heat is absorbed Answer: (C)
SI unit of thermal conductivity is – (A) W/m·K (B) J/kg·K (C) Cal/m·s·K (D) W/cm·K Answer: (A)
SI unit of frequency is – (A) Hertz (B) Radian (C) Second (D) Newton Answer: (A)
A good reflector of sound is – (A) Cloth (B) Water (C) Concrete wall (D) Curtain Answer: (C)
A ball dropped from height has – (A) Constant velocity (B) Constant momentum (C) Increasing speed (D) Zero force Answer: (C)
A dyne is the CGS unit of – (A) Pressure (B) Force (C) Energy (D) Momentum Answer: (B)