I85PREP
⌘ K
Kochi Entrance Science study materials
Kochi Entrance Science study resources

Kochi Entrance Science practice questions

One question at a time. Build your Kochi Entrance Science understanding.

First 50 of 200 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

Continue in the practice tool above to load more questions, 50 at a time.

Question 1Physics - Mechanics

A body moves along a straight line with constant acceleration. Which quantity-time graph is a straight line with non-zero slope?

  1. Velocity versus time Correct answer.
  2. Velocity versus displacement for non-zero acceleration
  3. Acceleration versus displacement
  4. Displacement versus time

Explanation

With constant acceleration, velocity changes at a fixed rate, so v = u + at is linear in time and its graph is a straight line whose slope equals the acceleration. Displacement versus time is a parabola, not a straight line, whenever acceleration is non-zero.

Question 2Physics - Mechanics

A stone is dropped from rest and falls freely near the Earth's surface. Taking g = 10 m s⁻², how far does it fall in the first 3 s?

  1. 15 m
  2. 45 m Correct answer.
  3. 30 m
  4. 90 m

Explanation

For free fall from rest, s = ½gt². Substituting g = 10 m s⁻² and t = 3 s gives s = ½ × 10 × 9 = 45 m. The initial velocity is zero, so no ut term contributes.

Question 3Physics - Mechanics

A projectile is launched with speed u at angle θ above the horizontal on level ground, with no air resistance. Which expression gives its horizontal range?

  1. u² cos 2θ / g
  2. u² sin 2θ / g Correct answer.
  3. 2u² sin θ / g
  4. u² sin²θ / (2g)

Explanation

Time of flight is 2u sin θ / g and horizontal velocity is u cos θ, so range equals (u cos θ)(2u sin θ / g) = u² sin 2θ / g. This peaks at θ = 45° where sin 2θ = 1.

Question 4Physics - Mechanics

A ball is thrown horizontally from a cliff of height 20 m with speed 15 m s⁻¹. Taking g = 10 m s⁻², how long does it take to reach the ground?

  1. 4.0 s
  2. 2.0 s Correct answer.
  3. 1.3 s
  4. 0.75 s

Explanation

Vertical motion is independent of the horizontal throw, so the fall time satisfies h = ½gt². Thus t = √(2h/g) = √(40/10) = 2 s, and the horizontal speed does not affect this time.

Question 5Physics - Mechanics

A body moves in a circle of radius 0.5 m at constant speed 4 m s⁻¹. What is the magnitude of its centripetal acceleration?

  1. 2 m s⁻²
  2. 16 m s⁻²
  3. 8 m s⁻²
  4. 32 m s⁻² Correct answer.

Explanation

Centripetal acceleration has magnitude v²/r. Here 4²/0.5 = 16/0.5 = 32 m s⁻², directed toward the centre of the circle.

Question 6Physics - Mechanics

A car travels 60 m at 20 m s⁻¹ and then 60 m at 30 m s⁻¹. What is its average speed over the whole journey?

  1. 24 m s⁻¹ Correct answer.
  2. 25 m s⁻¹
  3. 26 m s⁻¹
  4. 50 m s⁻¹

Explanation

Average speed is total distance divided by total time, not the mean of the speeds. The times are 3 s and 2 s, so total time is 5 s for 120 m, giving 24 m s⁻¹.

Question 7Physics - Mechanics

A block slides down a frictionless incline of angle 30° to the horizontal. Taking g = 10 m s⁻², what is its acceleration along the incline?

  1. 8.7 m s⁻²
  2. 10 m s⁻²
  3. 5 m s⁻² Correct answer.
  4. 0 m s⁻²

Explanation

The only force along a frictionless incline is the component of weight, mg sin θ. Dividing by mass gives a = g sin 30° = 10 × 0.5 = 5 m s⁻² down the slope.

Question 8Physics - Mechanics

A body moves under a constant net force. Which statement about its motion is necessarily true?

  1. Its speed must increase
  2. Its acceleration is constant in both magnitude and direction Correct answer.
  3. Its velocity is constant
  4. Its momentum is constant

Explanation

Newton's second law states that net force equals mass times acceleration. A constant net force on a fixed mass therefore gives a constant acceleration vector, while velocity changes at a steady rate.

Question 9Physics - Mechanics

A 2 kg object and a 6 kg object experience the same constant net force. How do their accelerations compare?

  1. The accelerations are equal only if the force is zero
  2. The 6 kg object has three times the acceleration of the 2 kg object
  3. The 2 kg object has three times the acceleration of the 6 kg object Correct answer.
  4. Both have the same acceleration

Explanation

Since a = F/m, acceleration is inversely proportional to mass for a fixed force. The lighter mass is one third of the heavier, so its acceleration is three times larger.

Question 10Physics - Mechanics

A 5 kg block rests on a horizontal floor. The coefficient of static friction is 0.4 and g = 10 m s⁻². What is the minimum horizontal force needed to start it moving?

  1. 2 N
  2. 20 N Correct answer.
  3. 50 N
  4. 12.5 N

Explanation

The normal force equals the weight, mg = 50 N, on level ground. The limiting static friction is μN = 0.4 × 50 = 20 N, so a horizontal force just above 20 N starts motion.

Question 11Physics - Mechanics

Two blocks of masses 3 kg and 2 kg are connected by a light string over a frictionless pulley, with the 3 kg block hanging and the 2 kg block on a frictionless horizontal table. Taking g = 10 m s⁻², what is the acceleration of the system?

  1. 2 m s⁻²
  2. 6 m s⁻² Correct answer.
  3. 10 m s⁻²
  4. 4 m s⁻²

Explanation

The driving force is the weight of the hanging block, 30 N, acting on the total mass of 5 kg. Hence a = 30/5 = 6 m s⁻², and the string tension is then 2 × 6 = 12 N.

Question 12Physics - Mechanics

A horizontal force of 40 N pushes a 10 kg crate across a rough floor at constant velocity. What is the coefficient of kinetic friction, taking g = 10 m s⁻²?

  1. 4.0
  2. 0.25
  3. 0.04
  4. 0.4 Correct answer.

Explanation

Constant velocity means the net horizontal force is zero, so kinetic friction equals the applied 40 N. The normal force is mg = 100 N, giving μ = 40/100 = 0.4.

Question 13Physics - Mechanics

A 0.2 kg ball hits a wall horizontally at 10 m s⁻¹ and rebounds horizontally at 6 m s⁻¹. What is the magnitude of the impulse on the ball?

  1. 0.8 N s
  2. 1.2 N s
  3. 3.2 N s Correct answer.
  4. 2.0 N s

Explanation

Impulse equals the change in momentum. Taking the initial direction as positive, Δp = m(v_final − v_initial) = 0.2 × (−6 − 10) = −3.2 N s, so the magnitude is 3.2 N s.

Question 14Physics - Mechanics

Two identical trolleys move toward each other, each at 2 m s⁻¹, and stick together after colliding. What is their common velocity afterward?

  1. 4 m s⁻¹
  2. 2 m s⁻¹ in the original direction of the first trolley
  3. 1 m s⁻¹
  4. Zero Correct answer.

Explanation

Total momentum before the collision is m(2) + m(−2) = 0 because the momenta are equal and opposite. Momentum conservation requires the combined mass to be at rest after they stick.

Question 15Physics - Mechanics

A force of 12 N acts on a body and displaces it 5 m in the direction of the force. What is the work done?

  1. 17 J
  2. 0 J
  3. 60 J Correct answer.
  4. 2.4 J

Explanation

Work is the product of force and displacement when they are parallel, W = Fd cos 0° = 12 × 5 = 60 J. The cosine factor is one because the force and displacement are in the same direction.

Question 16Physics - Mechanics

A 2 kg body moves at 3 m s⁻¹. What is its kinetic energy?

  1. 18 J
  2. 9 J Correct answer.
  3. 6 J
  4. 3 J

Explanation

Kinetic energy is ½mv², so ½ × 2 × 3² = 9 J. The speed is squared, so doubling the speed would quadruple the kinetic energy.

Question 17Physics - Mechanics

A pump raises 200 kg of water through a height of 10 m in 5 s. Taking g = 10 m s⁻², what is its useful output power?

  1. 400 W
  2. 20000 W
  3. 2000 W
  4. 4000 W Correct answer.

Explanation

The work done against gravity is mgh = 200 × 10 × 10 = 20 000 J. Dividing by the time of 5 s gives a power of 4000 W.

Question 18Physics - Mechanics

A spring of spring constant 200 N m⁻¹ is compressed by 0.1 m. How much elastic potential energy is stored?

  1. 0.5 J
  2. 1 J Correct answer.
  3. 2 J
  4. 20 J

Explanation

Elastic potential energy is ½kx², so ½ × 200 × (0.1)² = ½ × 200 × 0.01 = 1 J. The compression is squared, so doubling it quadruples the stored energy.

Question 19Physics - Mechanics

A machine lifts a load using 500 J of input energy and delivers 350 J of useful work. What is its efficiency?

  1. 30%
  2. 35%
  3. 70% Correct answer.
  4. 143%

Explanation

Efficiency is useful output divided by total input, expressed as a percentage. Here 350/500 = 0.70, which is 70%, and the remaining 150 J is lost, mainly as heat.

Question 20Physics - Mechanics

A body of mass 4 kg is at rest. A constant force of 8 N acts on it for 3 s. What is its final speed?

  1. 24 m s⁻¹
  2. 6 m s⁻¹ Correct answer.
  3. 1.5 m s⁻¹
  4. 2 m s⁻¹

Explanation

Acceleration is F/m = 8/4 = 2 m s⁻². Using v = u + at with u = 0 gives v = 2 × 3 = 6 m s⁻¹.

Question 21Physics - Mechanics

A particle moves with simple harmonic motion of amplitude 0.05 m and angular frequency 20 rad s⁻¹. What is its maximum speed?

  1. 1.0 m s⁻¹ Correct answer.
  2. 4.0 m s⁻¹
  3. 0.25 m s⁻¹
  4. 0.05 m s⁻¹

Explanation

In simple harmonic motion the maximum speed is ωA, attained at the equilibrium position. Here 20 × 0.05 = 1.0 m s⁻¹.

Question 22Physics - Mechanics

A satellite orbits the Earth in a circular orbit. If the orbital radius is increased while the speed is adjusted to keep the orbit circular, how does the orbital period change?

  1. It increases Correct answer.
  2. It becomes zero
  3. It decreases
  4. It stays the same

Explanation

Kepler's third law for circular orbits gives T² proportional to r³, so a larger radius means a longer period. The satellite moves more slowly at greater distance and travels a longer path.

Question 23Physics - Mechanics

A uniform metre rule is pivoted at its centre and balances when a 2 N weight hangs 20 cm to the left of the pivot. Where must a 4 N weight be placed on the right to balance it?

  1. 10 cm from the pivot Correct answer.
  2. 40 cm from the pivot
  3. 5 cm from the pivot
  4. 20 cm from the pivot

Explanation

For rotational balance the clockwise and anticlockwise moments must be equal. The left moment is 2 × 0.20 = 0.40 N m, so the right distance is 0.40/4 = 0.10 m, that is 10 cm.

Question 24Physics - Mechanics

A force of 10 N acts at 0.3 m from a pivot, perpendicular to the lever arm. What is the moment about the pivot?

  1. 0.03 N m
  2. 3 N m Correct answer.
  3. 33 N m
  4. 0.3 N m

Explanation

The moment of a force is the product of the force and the perpendicular distance from the pivot, so 10 × 0.3 = 3 N m. The force is perpendicular to the arm, so no sine factor is needed.

Question 25Physics - Mechanics

A body of mass 2 kg is lifted vertically at constant speed through 3 m. Taking g = 10 m s⁻², what is the change in its gravitational potential energy?

  1. 30 J
  2. 20 J
  3. 60 J Correct answer.
  4. 0 J

Explanation

Change in gravitational potential energy equals mgh, so 2 × 10 × 3 = 60 J. At constant speed the kinetic energy does not change, so all the work done goes into potential energy.

Question 26Physics - Mechanics

A stone is thrown vertically upward with an initial speed of 20 m s⁻¹. Taking g = 10 m s⁻² and neglecting air resistance, how long does the stone take to return to the thrower's hand?

  1. 8 s
  2. 2 s
  3. 1 s
  4. 4 s Correct answer.

Explanation

For vertical motion under gravity alone, the time to rise to the highest point is u/g = 20/10 = 2 s, and the descent takes an equal time because the motion is symmetric about the peak. The total time of flight is therefore 2 + 2 = 4 s.

Question 27Physics - Mechanics

Which quantity is a vector, having both magnitude and direction, in the study of linear motion?

  1. Time
  2. Distance
  3. Speed
  4. Displacement Correct answer.

Explanation

Displacement is defined as the change in position, so it carries a direction as well as a magnitude and can be negative or zero for a closed path. Distance, speed and time are scalars specified by magnitude alone.

Question 28Physics - Mechanics

A body starts from rest and moves in a straight line with uniform acceleration. It covers 25 m in the first 5 s. What is its acceleration?

  1. 2 m s⁻² Correct answer.
  2. 5 m s⁻²
  3. 1 m s⁻²
  4. 10 m s⁻²

Explanation

Using s = ut + ½at² with u = 0 gives 25 = ½a(5)² = 12.5a, so a = 2 m s⁻². Equivalently, the average speed over the interval is 5 m s⁻¹ and the final speed is 10 m s⁻¹, giving a = 10/5 = 2 m s⁻².

Question 29Physics - Mechanics

A ball is projected horizontally at 15 m s⁻¹ from the top of a tower 20 m high. Taking g = 10 m s⁻² and neglecting air resistance, how far from the base of the tower does it land?

  1. 15 m
  2. 30 m Correct answer.
  3. 20 m
  4. 45 m

Explanation

The vertical fall time follows from h = ½gt², so 20 = 5t² and t = 2 s. The horizontal velocity is unchanged because gravity acts vertically, so the range is 15 × 2 = 30 m.

Question 30Physics - Mechanics

A particle moves in a straight line. Its velocity–time graph is a straight line that starts at 8 m s⁻¹ at t = 0 and reaches 0 m s⁻¹ at t = 4 s, continuing with the same slope afterwards. What is the displacement of the particle during the interval t = 0 to t = 6 s?

  1. 16 m
  2. 8 m
  3. 4 m Correct answer.
  4. 12 m

Explanation

The slope gives a constant acceleration of (0 − 8)/4 = −2 m s⁻². For the first 4 s the displacement is the triangular area ½ × 4 × 8 = 16 m; for the next 2 s the particle moves from rest with a = −2 m s⁻², giving ½ × (−2) × 2² = −4 m. The net displacement is 16 − 4 = 4 m.

Question 31Physics - Waves, Electricity and Magnetism

A sound wave travels through air with a frequency of 500 Hz. If the speed of sound in air is 340 m/s, what is the wavelength?

  1. 0.34 m
  2. 170 m
  3. 0.68 m Correct answer.
  4. 1.47 m

Explanation

The wave equation v = fλ relates speed, frequency and wavelength, so λ = v/f. Substituting gives λ = 340/500 = 0.68 m. The wavelength is the distance the wave advances in one full oscillation.

Question 32Physics - Waves, Electricity and Magnetism

In a transverse wave travelling along a stretched string, which statement correctly describes the motion of the particles of the medium?

  1. They remain completely stationary while energy passes.
  2. They oscillate parallel to the direction of energy propagation.
  3. They travel along the string with the wave at the wave speed.
  4. They oscillate perpendicular to the direction of energy propagation. Correct answer.

Explanation

By definition, in a transverse wave the displacement of the medium is perpendicular to the direction in which the wave travels. Energy is transported along the string, but the particles themselves only vibrate about fixed equilibrium positions.

Question 33Physics - Waves, Electricity and Magnetism

Which of the following electromagnetic waves has the longest wavelength?

  1. Radio waves Correct answer.
  2. Visible light
  3. Ultraviolet radiation
  4. X-rays

Explanation

In the electromagnetic spectrum, radio waves lie at the long-wavelength, low-frequency end. Wavelength decreases through visible light and ultraviolet to X-rays, which have very short wavelengths.

Question 34Physics - Waves, Electricity and Magnetism

A resistor of 12 Ω carries a current of 0.5 A. What is the potential difference across it?

  1. 24 V
  2. 6 V Correct answer.
  3. 0.04 V
  4. 12.5 V

Explanation

Ohm's law states V = IR for a conductor at constant temperature. Substituting I = 0.5 A and R = 12 Ω gives V = 6 V. The voltage is the product of current and resistance.

Question 35Physics - Waves, Electricity and Magnetism

Two point charges are separated by a certain distance in a vacuum. If the distance between them is doubled while the charges stay the same, the electrostatic force between them becomes

  1. one half of its original value
  2. one quarter of its original value Correct answer.
  3. twice its original value
  4. four times its original value

Explanation

Coulomb's law states that the force is inversely proportional to the square of the separation, F ∝ 1/r². Doubling r multiplies the force by 1/2² = 1/4. Hence the force falls to a quarter of its original magnitude.

Question 36Physics - Waves, Electricity and Magnetism

Which unit is used to express the magnetic flux density (magnetic field strength) in SI units?

  1. Henry
  2. Weber
  3. Tesla Correct answer.
  4. Farad

Explanation

Magnetic flux density B is measured in tesla, where one tesla equals one weber per square metre. The tesla also equals one newton per ampere-metre, reflecting the force on a current-carrying conductor.

Question 37Physics - Waves, Electricity and Magnetism

A convex lens has a focal length of 10 cm. An object is placed 30 cm from the lens. Where is the image formed?

  1. 30 cm on the same side as the object
  2. 10 cm on the opposite side of the lens
  3. 15 cm on the opposite side of the lens Correct answer.
  4. 7.5 cm on the opposite side of the lens

Explanation

The thin-lens equation 1/f = 1/u + 1/v gives 1/v = 1/10 − 1/30 = 2/30, so v = 15 cm. A positive image distance for a real object means the image forms on the opposite side of the lens and is real and inverted.

Question 38Physics - Waves, Electricity and Magnetism

A wave of frequency 250 Hz travels along a string at 100 m/s. What is the phase difference between two points on the string that are 0.2 m apart?

  1. π/4 radians
  2. π radians Correct answer.
  3. π/2 radians
  4. 2π radians

Explanation

The wavelength is λ = v/f = 100/250 = 0.4 m. A separation of 0.2 m is exactly half a wavelength, and half a wavelength corresponds to a phase difference of π radians. Points half a wavelength apart oscillate in antiphase.

Question 39Physics - Waves, Electricity and Magnetism

In a stationary wave on a string fixed at both ends, the distance between two adjacent nodes is 0.25 m. What is the wavelength of the component travelling waves?

  1. 1.0 m
  2. 0.5 m Correct answer.
  3. 0.125 m
  4. 0.25 m

Explanation

In a stationary wave, adjacent nodes are separated by half a wavelength. Therefore λ = 2 × 0.25 = 0.5 m. The same spacing separates adjacent antinodes.

Question 40Physics - Waves, Electricity and Magnetism

Two resistors of 4 Ω and 6 Ω are connected in parallel across a 12 V supply. What is the total current drawn from the supply?

  1. 2 A
  2. 1.2 A
  3. 0.83 A
  4. 5 A Correct answer.

Explanation

The parallel equivalent resistance is 1/R = 1/4 + 1/6 = 5/12, so R = 2.4 Ω. The total current is I = V/R = 12/2.4 = 5 A. Equivalently, the branch currents 3 A and 2 A add to 5 A.

Question 41Physics - Waves, Electricity and Magnetism

A wire of length 0.5 m carrying a current of 2 A lies perpendicular to a uniform magnetic field of flux density 0.4 T. What is the magnitude of the force on the wire?

  1. 0.8 N
  2. 1.6 N
  3. 0.2 N
  4. 0.4 N Correct answer.

Explanation

The force on a current-carrying conductor is F = BIL sin θ, and here θ = 90° so sin θ = 1. Substituting gives F = 0.4 × 2 × 0.5 = 0.4 N. The force is perpendicular to both the field and the current.

Question 42Physics - Waves, Electricity and Magnetism

A capacitor of 20 μF is charged to a potential difference of 50 V. How much energy is stored?

  1. 0.025 J Correct answer.
  2. 0.05 J
  3. 1.0 J
  4. 0.0025 J

Explanation

The energy stored in a capacitor is E = ½CV². Substituting C = 20 × 10⁻⁶ F and V = 50 V gives E = ½ × 20 × 10⁻⁶ × 2500 = 0.025 J. The half factor arises because the voltage rises from zero as charge accumulates.

Question 43Physics - Waves, Electricity and Magnetism

In the photoelectric effect, increasing the intensity of incident light of fixed frequency above the threshold causes which change?

  1. The maximum kinetic energy of emitted electrons increases.
  2. The threshold frequency of the metal decreases.
  3. The stopping potential increases in magnitude.
  4. More photoelectrons are emitted per second, with the same maximum kinetic energy. Correct answer.

Explanation

Intensity determines the number of photons arriving per second, so a higher intensity releases more electrons per second. The maximum kinetic energy depends only on the photon frequency and the work function, not on intensity.

Question 44Physics - Waves, Electricity and Magnetism

Which phenomenon provides the strongest evidence that light behaves as a wave?

  1. Compton scattering of X-rays
  2. Interference fringes from a double slit Correct answer.
  3. Black-body radiation spectrum
  4. The photoelectric effect

Explanation

Interference and diffraction arise from the superposition of waves and cannot be explained by classical particles. The double-slit fringe pattern is therefore direct evidence of the wave nature of light.

Question 45Physics - Waves, Electricity and Magnetism

A step-down transformer has 1000 turns on its primary coil and 50 turns on its secondary. If the primary is supplied with 240 V alternating current, what is the secondary voltage (ideal transformer)?

  1. 48 V
  2. 12 V Correct answer.
  3. 4.8 V
  4. 4800 V

Explanation

For an ideal transformer the voltage ratio equals the turns ratio: Vs/Vp = Ns/Np. Thus Vs = 240 × 50/1000 = 12 V. A step-down transformer reduces voltage while increasing the available current.

Question 46Physics - Waves, Electricity and Magnetism

A charged particle moves in a circle in a uniform magnetic field because the magnetic force

  1. acts perpendicular to the velocity, providing a centripetal force without doing work Correct answer.
  2. opposes the motion and gradually slows the particle
  3. does work on the particle and increases its speed
  4. acts along the velocity, accelerating the particle in a straight line

Explanation

The magnetic force on a moving charge is F = qv × B, which is always perpendicular to velocity. A perpendicular force changes direction but not speed, so it acts as a centripetal force and does no work. Hence the particle moves in a circle at constant speed.

Question 47Physics - Waves, Electricity and Magnetism

A pipe closed at one end resonates at its fundamental frequency of 170 Hz. Taking the speed of sound as 340 m/s, what is the length of the pipe?

  1. 0.25 m
  2. 0.5 m Correct answer.
  3. 1.0 m
  4. 2.0 m

Explanation

A pipe closed at one end has a fundamental wavelength of four times its length: λ = 4L. Since λ = v/f = 340/170 = 2 m, the length is L = 2/4 = 0.5 m. The closed end is a node and the open end an antinode.

Question 48Physics - Waves, Electricity and Magnetism

A ray of light passes from air into glass of refractive index 1.5 at an angle of incidence of 30°. What is the angle of refraction?

  1. 19.5° Correct answer.
  2. 60°
  3. 30°
  4. 48.6°

Explanation

Snell's law gives n₁ sin θ₁ = n₂ sin θ₂, so sin θ₂ = (1.0 × sin 30°)/1.5 = 0.333. The angle whose sine is 0.333 is about 19.5°. The ray bends towards the normal on entering the denser medium.

Question 49Physics - Waves, Electricity and Magnetism

In a double-slit experiment the slit separation is doubled and the screen distance is halved. How does the fringe spacing change?

  1. It becomes one quarter of the original spacing. Correct answer.
  2. It becomes one half of the original spacing.
  3. It doubles.
  4. It remains unchanged.

Explanation

Fringe spacing is given by w = λD/d, where D is the screen distance and d the slit separation. Doubling d halves the spacing, and halving D halves it again, giving a quarter of the original. The two effects multiply.

Question 50Physics - Waves, Electricity and Magnetism

A battery of emf 12 V and internal resistance 2 Ω is connected to an external resistor of 4 Ω. What is the terminal potential difference across the battery?

  1. 8 V Correct answer.
  2. 4 V
  3. 12 V
  4. 6 V

Explanation

The current is I = emf/(R + r) = 12/6 = 2 A. The terminal voltage is V = emf − Ir = 12 − 2×2 = 8 V, which equals the voltage across the external resistor, IR = 8 V. The lost volts appear across the internal resistance.