Q1.What is the primary source of energy for Earth's seasons?
A.Earth's rotation
Tilt of Earth's axis
C.Gravitational pull of the Moon
D.Solar flares
Explanation: The tilt of Earth's axis (approximately 23.5°) causes variations in the angle of sunlight throughout the year, leading to the seasons.
Q2.Which of the following best describes the term 'friction'?
A.A force that accelerates objects
A force that opposes the relative motion between two surfaces
C.A force that attracts objects toward each other
D.A force that causes objects to move in a circle
Explanation: Friction is a contact force that opposes the relative motion or tendency of motion between two surfaces in contact.
Q3.What type of wave is a sound wave?
A.Electromagnetic wave
B.Transverse wave
Longitudinal wave
D.Surface wave
Explanation: Sound waves are longitudinal waves, meaning the particles of the medium vibrate parallel to the direction of wave propagation.
Q4.Which of the following devices converts electrical energy into mechanical energy?
A.Generator
Motor
C.Transformer
D.Capacitor
Explanation: An electric motor converts electrical energy into mechanical energy, often used to drive machinery or appliances.
Q5.What is the primary purpose of a lens in a camera?
A.To reflect light
B.To absorb light
To focus light onto the sensor or film
D.To polarize light
Explanation: The lens in a camera focuses light from the object onto the sensor or film to form a clear image.
Q6.Which of the following is a characteristic of alpha particles?
A.They are electromagnetic waves
B.They have high penetrating power
They are helium nuclei
D.They are not deflected by magnetic fields
Explanation: Alpha particles are helium nuclei, consisting of 2 protons and 2 neutrons, emitted during alpha decay.
Q7.What is the main source of energy for Earth's wind systems?
A.Gravitational pull of the Moon
Solar radiation
C.Earth's magnetic field
D.Geothermal heat
Explanation: Solar radiation causes uneven heating of Earth's surface, creating pressure differences that drive wind systems.
Q8.Which of the following best describes the term 'momentum'?
A.The energy stored in a moving object
The product of an object's mass and velocity
C.The force exerted by an object at rest
D.The acceleration of an object in motion
Explanation: Momentum is defined as the product of an object's mass and velocity, a vector quantity conserved in isolated systems.
Q9.What happens to the density of a substance when it is heated at constant pressure?
A.It increases
It decreases
C.It remains the same
D.It becomes zero
Explanation: When a substance is heated at constant pressure, it expands, increasing its volume and decreasing its density (density = mass/volume).
Q10.Which of the following is a characteristic of a good electrical insulator?
A.High electrical conductivity
Low electrical conductivity
C.High thermal conductivity
D.High density
Explanation: A good electrical insulator has low electrical conductivity, preventing the flow of electric current (e.g., rubber, glass).
Q11.What type of mirror is used in a solar cooker?
A.Plane mirror
B.Convex mirror
Concave mirror
D.Parabolic mirror
Explanation: A concave mirror is used in a solar cooker because it focuses sunlight to a point, concentrating heat for cooking.
Q12.Which of the following is a non-renewable source of energy?
A.Solar energy
B.Wind energy
Coal
D.Hydropower
Explanation: Coal is a non-renewable source of energy because it is a fossil fuel formed over millions of years and cannot be replenished on a human timescale.
Q13.What is the primary cause of the Coriolis effect on Earth?
A.Gravitational pull of the Moon
Earth's rotation
C.Solar radiation
D.Earth's magnetic field
Explanation: The Coriolis effect is caused by Earth's rotation, which deflects moving objects (like winds and ocean currents) due to the planet's spin.
Q14.Which of the following instruments is used to measure temperature?
A.Barometer
Thermometer
C.Hygrometer
D.Anemometer
Explanation: A thermometer is used to measure temperature, often using mercury, alcohol, or digital sensors.
Q15.What type of image is formed by a plane mirror?
A.Real and inverted
Virtual and upright
C.Real and upright
D.Virtual and inverted
Explanation: A plane mirror forms a virtual, upright image that is the same size as the object and appears to be behind the mirror.
Q16.Which of the following is a characteristic of a diverging lens?
A.It always forms real images
B.It converges light rays
It forms virtual, upright images
D.It is thicker at the center than at the edges
Explanation: A diverging lens (concave lens) always forms virtual, upright, and diminished images, regardless of the object's position.
Q17.What is the effect of connecting resistors in parallel in a circuit?
A.The total resistance increases
The total resistance decreases
C.The total resistance remains the same
D.The voltage across each resistor increases
Explanation: In a parallel circuit, the total resistance decreases because the reciprocal of the total resistance is the sum of the reciprocals of the individual resistances.
Q18.Which of the following particles is emitted during alpha decay?
A.Electron
B.Neutron
Helium nucleus
D.Proton
Explanation: Alpha decay involves the emission of an alpha particle, which is a helium nucleus (2 protons and 2 neutrons).
Q19.What is the primary source of energy for Earth's volcanic activity?
A.Solar radiation
Geothermal heat
C.Gravitational pull of the Moon
D.Nuclear fission
Explanation: Geothermal heat from the Earth's interior, generated by radioactive decay and residual heat from the planet's formation, drives volcanic activity.
Q20.Which of the following is a fundamental unit in the SI system?
A.Newton
B.Joule
Kilogram
D.Watt
Explanation: The kilogram is a fundamental unit in the SI system, used to measure mass. Newton, joule, and watt are derived units.
Q21.What is the main purpose of a capacitor in an electrical circuit?
A.To increase resistance
To store electrical energy
C.To convert AC to DC
D.To step up voltage
Explanation: A capacitor stores electrical energy in an electric field between its plates and can release it when needed.
Q22.Which of the following best describes the term 'work' in physics?
A.The speed of an object in motion
B.The force exerted by an object at rest
The transfer of energy when a force moves an object through a distance
D.The acceleration of an object in a straight line
Explanation: Work in physics is defined as the transfer of energy that occurs when a force is applied to an object over a distance (W = F * d * cosθ).
Q23.What type of energy is associated with the motion of an object?
A.Potential energy
Kinetic energy
C.Thermal energy
D.Chemical energy
Explanation: Kinetic energy is the energy an object possesses due to its motion, given by KE = (1/2)mv^2.
Q24.Which of the following is a unit of pressure?
A.Joule
B.Newton
Pascal
D.Watt
Explanation: The pascal (Pa) is the unit of pressure, defined as force per unit area (1 Pa = 1 N/m^2).
Q25.What is the primary difference between a conductor and an insulator?
A conductor allows electric current to flow easily, an insulator does not
B.A conductor has a higher resistance than an insulator
C.A conductor is always a metal, an insulator is not
D.A conductor stores energy, an insulator does not
Explanation: A conductor allows electric current to flow easily due to low resistance (e.g., metals), while an insulator resists the flow of current (e.g., rubber).
Q26.Which of the following is a property of X-rays?
A.They are charged particles
B.They have low penetrating power
They are electromagnetic waves
D.They are deflected by magnetic fields
Explanation: X-rays are electromagnetic waves with high energy and penetrating power, used in medical imaging.
Q27.What is the main advantage of using a step-up transformer in power distribution?
A.It increases the current in the circuit
It reduces energy loss during transmission
C.It decreases the voltage for safety
D.It converts DC to AC
Explanation: A step-up transformer increases voltage, reducing current and thus minimizing energy loss (I^2R) during long-distance power transmission.
Q28.Which of the following is a characteristic of a good thermal conductor?
A.Low thermal conductivity
High thermal conductivity
C.Low density
D.Low electrical conductivity
Explanation: A good thermal conductor has high thermal conductivity, allowing heat to transfer easily (e.g., metals like copper).
Q29.What is the primary source of energy for Earth's earthquakes?
A.Solar radiation
B.Geothermal heat
Tectonic plate movements
D.Gravitational pull of the Moon
Explanation: Earthquakes are primarily caused by the movement of tectonic plates, which release stored energy along faults.
Q30.A car accelerates uniformly from rest to 20 ms^-1 in 5 s. What is its acceleration?
A.2 ms^-2
4 ms^-2
C.6 ms^-2
D.8 ms^-2
Explanation: Acceleration a = (v - u) / t = (20 - 0) / 5 = 4 ms^-2.
Q31.A 2 kg mass is dropped from a height of 10 m. What is its velocity just before it hits the ground? (g = 10 ms^-2, neglect air resistance)
Q33.A 12 V battery is connected to a 4 Ω resistor. What is the current flowing through the resistor?
A.2 A
3 A
C.4 A
D.6 A
Explanation: Using Ohm’s law: I = V / R = 12 / 4 = 3 A.
Q34.What is the primary source of energy for Earth's lightning?
A.Solar radiation
B.Geothermal heat
Charge separation in clouds
D.Gravitational pull of the Moon
Explanation: Lightning is caused by the separation of charges within clouds, driven by the movement of water droplets and ice particles, leading to a discharge of electrical energy.
Q35.Which of the following best describes the term 'refraction'?
The bending of light as it passes from one medium to another
B.The reflection of light off a surface
C.The absorption of light by a medium
D.The scattering of light in all directions
Explanation: Refraction is the bending of light as it passes from one medium to another with a different refractive index, due to a change in speed.
Q36.What type of wave is a light wave?
A.Longitudinal wave
Transverse wave
C.Mechanical wave
D.Surface wave
Explanation: Light waves are transverse waves, with electric and magnetic fields oscillating perpendicular to the direction of propagation.
Q37.Which of the following devices converts light energy into electrical energy?
A.Electric motor
Solar cell
C.Transformer
D.Capacitor
Explanation: A solar cell (photovoltaic cell) converts light energy directly into electrical energy using the photovoltaic effect.
Q38.What is the primary purpose of a prism in optics?
A.To reflect light
B.To focus light
To disperse light into its colors
D.To polarize light
Explanation: A prism disperses white light into its constituent colors (spectrum) by refracting different wavelengths of light at different angles.
Q39.Which of the following is a characteristic of a nuclear fission reaction?
A.It involves the combination of two light nuclei
It involves the splitting of a heavy nucleus
C.It produces gamma rays only
D.It does not release energy
Explanation: Nuclear fission involves the splitting of a heavy nucleus (e.g., uranium-235) into two smaller nuclei, releasing energy in the process.
Q40.What is the SI unit of electric charge?
A.Ampere
Coulomb
C.Volt
D.Ohm
Explanation: The SI unit of electric charge is the coulomb (C), which measures the quantity of electric charge.