Physics- 1 - Free MCQ Practice Test with solutions, SSC CGL

Newton’s First Law (Law of Inertia) correctly states that an object remains at rest or in uniform motion unless an external force acts on it. Newton’s Second Law, however, states that acceleration is directly proportional to the net force and inversely proportional to mass (F = ma), making Statement 2 incorrect.

Acceleration is the rate of change of velocity. Since the body moves with constant speed in a straight line, its velocity is constant, and thus, acceleration is zero.

Velocity is a vector quantity as it has both magnitude and direction. Speed, work, and power are scalar quantities, as they only have magnitude.

Newton’s Universal Law of Gravitation states that the force (F) between two objects is directly proportional to the product of their masses (m_₁m_₂) and inversely proportional to the square of the distance (r²) between them, i.e., F = G(m_₁m_₂)/r².

Work is done when a force causes displacement in its direction (W = F·d·cosθ). However, work is a scalar quantity, not a vector, as it has no direction, making Statement 2 incorrect.

Pascal’s Law states that pressure applied to a confined fluid is transmitted equally in all directions. This principle is used in hydraulic lifts to amplify force.

Sound waves are longitudinal waves, where particle displacement is parallel to the direction of wave propagation. Light and radio waves are transverse, and water waves are a combination of both.

The power of a lens is defined as the reciprocal of its focal length (in meters) and is measured in dioptres (D). Watt is for power, joule for energy, and candela for luminous intensity.

Conduction is the primary mode of heat transfer in solids due to particle vibration. Radiation, however, does not require a medium and can occur in a vacuum, making Statement 2 incorrect.

The SI unit of electric current is the ampere (A). Volt is for potential difference, ohm for resistance, and watt for power.

A rainbow is formed due to the dispersion of sunlight by water droplets, where different wavelengths of light are refracted at different angles, creating a spectrum of colors.

Specific heat capacity is the heat required to raise the temperature of 1 kg of a substance by 1°C without changing its state. Latent heat is associated with state changes.

Magnetic fields can pass through a vacuum (e.g., in space). They are vector quantities, produced by moving charges or magnets, and exert a force on moving charges (Lorentz force).

A lever increases mechanical advantage by amplifying force or distance. However, no machine is 100% efficient due to energy losses (e.g., friction), making Statement 2 incorrect.

Sound travels fastest in solids (e.g., steel) due to higher particle density and stronger intermolecular forces, followed by liquids (water), gases (air), and it cannot travel in a vacuum.

Faraday’s Law states that the induced electromotive force (EMF) in a circuit is proportional to the rate of change of magnetic flux through the circuit.

Alpha particles are helium nuclei (2 protons, 2 neutrons). Gamma rays are high-energy electromagnetic waves, similar to X-rays, emitted during radioactive decay.

The human eye’s lens is a convex lens, which converges light to form real images on the retina. Concave lenses diverge light, and mirrors do not apply here.

Bernoulli’s Principle explains the lift in an airplane wing, where faster air over the wing reduces pressure, creating lift. Floating ships and submarines relate to Archimedes’ Principle, and hydraulic brakes use Pascal’s Law.

Protons carry a positive charge in an atom’s nucleus. Electrons are negatively charged, neutrons are neutral, and photons are massless particles of light.