The center of gravity of a regular object lies – (A) At its base (B) At its center (C) Outside the body (D) At the lowest point Answer: (B)
The property of light responsible for formation of shadows is – (A) Diffraction (B) Reflection (C) Rectilinear propagation (D) Refraction Answer: (C)
The SI unit of electric power is – (A) Volt (B) Joule (C) Watt (D) Coulomb Answer: (C)
A permanent magnet is made from – (A) Soft iron (B) Hardened steel (C) Copper (D) Aluminum Answer: (B)
A device used to measure humidity is – (A) Thermometer (B) Barometer (C) Hygrometer (D) Manometer Answer: (C)
Ringing of a bell in vacuum is not heard because – (A) Sound is absorbed (B) Air is absent (C) Gravity is low (D) Vibration is weak Answer: (B)
The least count of a vernier caliper is usually – (A) 1 cm (B) 0.1 mm (C) 0.01 mm (D) 0.001 mm Answer: (C)
The unit of magnetic permeability is – (A) H/m (B) Wb (C) T·m² (D) A·m Answer: (A)
A hydrometer measures – (A) Volume (B) Density (C) Viscosity (D) Specific gravity Answer: (D)
Red shift in light from a star indicates – (A) Star is moving toward us (B) Star is stationary (C) Star is moving away (D) Star is collapsing Answer: (C)
EM waves carry – (A) Only electric energy (B) Only magnetic energy (C) Both electric and magnetic energy (D) Mechanical energy Answer: (C)
The modulus of rigidity is associated with – (A) Longitudinal strain (B) Shear strain (C) Volumetric strain (D) Elastic strain Answer: (B)
The function of control rods in a nuclear reactor is to – (A) Absorb neutrons (B) Produce heat (C) Speed up fission (D) Cool down the core Answer: (A)
The speed of light depends on – (A) Frequency (B) Medium (C) Amplitude (D) Source Answer: (B)
The angle of minimum deviation in a prism occurs when – (A) Refraction is minimum (B) Light passes symmetrically (C) Refraction equals reflection (D) Total internal reflection occurs Answer: (B)
The optical center of a lens is – (A) Geometric center (B) Point where refraction does not deviate ray (C) Focal point (D) Vertex Answer: (B)
The least resistance is offered by – (A) Silver (B) Copper (C) Aluminum (D) Gold Answer: (A)
The earth’s magnetic field is due to – (A) Magnet in the core (B) Electric currents in the core (C) Iron in crust (D) Gravity Answer: (B)
A multimeter is used to measure – (A) Voltage only (B) Current only (C) Resistance only (D) All of the above Answer: (D)
A Nuclear bomb is based on – (A) Controlled fission (B) Fusion (C) Uncontrolled fission (D) Radioactive decay Answer: (C)
The unit of strain is – (A) N/m² (B) No unit (dimensionless) (C) m (D) kg/m² Answer: (B)
A lens that converges parallel rays to a point is – (A) Concave (B) Convex (C) Plane (D) Cylindrical Answer: (B)
Specific heat is highest for – (A) Mercury (B) Iron (C) Water (D) Lead Answer: (C)
The device that works on the principle of mutual induction is – (A) Transformer (B) Generator (C) Motor (D) Rectifier Answer: (A)
A gas thermometer works best because – (A) Gases expand more (B) Gases are accurate at low temp (C) Gases obey laws over wider range (D) Gas temperature is high Answer: (C)
Radio waves have the – (A) Longest wavelength (B) Shortest wavelength (C) Highest frequency (D) Most energy Answer: (A)
Torque is zero when – (A) Force is zero (B) Lever arm is zero (C) Force is parallel to lever arm (D) All of the above Answer: (D)
The eye defect caused by non-uniform curvature is – (A) Myopia (B) Hypermetropia (C) Astigmatism (D) Presbyopia Answer: (C)
Wavelength and frequency of light are related by – (A) λ = f/v (B) v = fλ (C) λ = v/f (D) f = λ/v Answer: (B)
The SI unit of illumination (illuminance) is – (A) Lumen (B) Lux (C) Candela (D) Watt Answer: (B)
A boiling liquid remains at constant temperature because – (A) Heat is lost (B) It is heated from below (C) Heat is used to change state (D) Vapor pressure is zero Answer: (C)
The sensitivity of a galvanometer can be increased by – (A) Increasing spring stiffness (B) Increasing magnetic field (C) Using thicker coil (D) None of these Answer: (B)
A mass attached to spring oscillates with frequency depending on – (A) Spring constant and amplitude (B) Mass and spring constant (C) Mass and amplitude (D) Mass and energy Answer: (B)
The period of revolution of a satellite depends on – (A) Radius of orbit (B) Mass of satellite (C) Shape of satellite (D) Altitude only Answer: (A)
The angle of contact for water and glass is – (A) 0° (B) < 90° (C) > 90° (D) 180° Answer: (B)
Escape velocity is derived using – (A) Newton’s 1st law (B) Newton’s 2nd law (C) Conservation of energy (D) Kepler’s law Answer: (C)
The voltage across an inductor is proportional to – (A) Current (B) Rate of change of current (C) Capacitance (D) Frequency Answer: (B)
The Buoyant force is equal to – (A) Weight of the fluid displaced (B) Volume of the object (C) Pressure of the liquid (D) Surface tension Answer: (A)
A material which allows partial current is – (A) Conductor (B) Insulator (C) Semiconductor (D) Dielectric Answer: (C)
The net work done in a circular path by conservative force is – (A) Maximum (B) Zero (C) Minimum (D) Infinite Answer: (B)
Infrared rays are used in – (A) Night vision (B) UV lamps (C) Microscopes (D) X-ray machines Answer: (A)
The color of an opaque object is the color it – (A) Reflects (B) Absorbs (C) Emits (D) Polarizes Answer: (A)
The half-life of a radioactive substance is – (A) Time to fully decay (B) Time to halve its mass (C) Time to halve its activity (D) Both B and C Answer: (D)
The heat energy per unit mass per degree rise in temperature is – (A) Latent heat (B) Specific heat (C) Calorific value (D) Entropy Answer: (B)
Photoelectric emission occurs only when – (A) Light intensity is high (B) Photon energy > work function (C) Frequency < threshold (D) Electrons gain kinetic energy Answer: (B)
A barometer measures – (A) Pressure of gas (B) Air pressure (C) Water level (D) Atmospheric temperature Answer: (B)
A compressed gas in a sealed container has – (A) Kinetic energy (B) Potential energy (C) Thermal energy (D) All of the above Answer: (D)
The main principle of radar is – (A) Reflection of sound (B) Refraction of light (C) Reflection of radio waves (D) Diffraction of waves Answer: (C)
A perfect black body is one that – (A) Reflects all radiation (B) Absorbs all radiation (C) Transmits all radiation (D) Blocks all radiation Answer: (B)
The solar constant is approx – (A) 100 W/m² (B) 1361 W/m² (C) 1.5 kW/m² (D) 340 W/m² Answer: (B)
