1. Home
  2. GK Questions
  3. General Science
  4. Mechanics

Mechanics — GK Questions with Answers

10 General Science Questions20 General Science Questions50 General Science Questions100 General Science Questions Current Affairs 2026 Today's GK Quiz Static GK हिन्दी
36 questions
  1. 1 newton equals how many dyne?
    1. 10³ dyne
    2. 10⁵ dyne
    3. 10⁷ dyne
    4. 10⁹ dyne
    Show answer

    Answer: (B) 10⁵ dyne

    1 N = 1 kg × 1 m/s² = 1000 g × 100 cm/s² = 10⁵ dyne. The newton is the SI unit and the dyne the CGS unit of force.

  2. Which of these is not an SI base unit?
    1. kelvin
    2. candela
    3. mole
    4. newton
    Show answer

    Answer: (D) newton

    The newton is a derived unit (kg·m/s²). Kelvin, candela and mole are among the seven base units.

  3. A light year is a unit of —
    1. distance
    2. time
    3. intensity of light
    4. speed
    Show answer

    Answer: (A) distance

    A light year is the distance light travels in one year — about 9.46 × 10¹⁵ m.

  4. Which pair has the same dimensions?
    1. work and power
    2. momentum and energy
    3. torque and work
    4. pressure and force
    Show answer

    Answer: (C) torque and work

    Torque and work are both [ML²T⁻²]. Still, torque is a vector and work is a scalar.

  5. If the radius of a sphere is measured with a 2% error, the error in its volume is —
    1. 2%
    2. 4%
    3. 6%
    4. 8%
    Show answer

    Answer: (C) 6%

    V ∝ r³, so the percentage error is 3 times: 3 × 2% = 6%.

  6. Which of these quantities is a vector?
    1. impulse
    2. work
    3. electric current
    4. pressure
    Show answer

    Answer: (A) impulse

    Impulse = force × time, which is a vector. Electric current has a direction but is a scalar, because it does not follow vector addition.

  7. What does the slope of a velocity–time graph give?
    1. displacement
    2. distance
    3. speed
    4. acceleration
    Show answer

    Answer: (D) acceleration

    The slope of a v-t graph gives acceleration and the area under it gives displacement.

  8. A person goes from A to B at 30 km/h and returns at 60 km/h. Average speed?
    1. 45 km/h
    2. 40 km/h
    3. 50 km/h
    4. 35 km/h
    Show answer

    Answer: (B) 40 km/h

    For equal distances, average speed = 2 × 30 × 60 ÷ (30 + 60) = 3600 ÷ 90 = 40 km/h.

  9. At the highest point of a ball thrown up —
    1. velocity is zero, acceleration is g
    2. velocity and acceleration are both zero
    3. velocity is maximum, acceleration is zero
    4. both are maximum
    Show answer

    Answer: (A) velocity is zero, acceleration is g

    At the highest point the ball stops for an instant (v = 0), but gravity still gives it acceleration g.

  10. The distances covered by a body falling from rest in the 1st, 2nd and 3rd seconds are in the ratio —
    1. 1 : 2 : 3
    2. 1 : 4 : 9
    3. 1 : 3 : 5
    4. 1 : 1 : 1
    Show answer

    Answer: (C) 1 : 3 : 5

    The distance in the nth second is in proportion to (2n − 1) — the odd numbers 1 : 3 : 5. Total distances are 1 : 4 : 9.

  1. What happens to the horizontal velocity in projectile motion?
    1. It keeps increasing
    2. It stays constant
    3. It keeps decreasing
    4. It becomes zero
    Show answer

    Answer: (B) It stays constant

    There is no force horizontally (without air), so the horizontal velocity u cosθ stays constant through the flight.

  2. Throwing at which two angles gives a projectile the same range?
    1. 30° and 45°
    2. 15° and 60°
    3. 40° and 60°
    4. 20° and 70°
    Show answer

    Answer: (D) 20° and 70°

    The range is equal for complementary angles (θ and 90° − θ); 20° + 70° = 90°.

  3. The range of a ball thrown at 20 m/s at 45° (g = 10) is —
    1. 20 m
    2. 10 m
    3. 80 m
    4. 40 m
    Show answer

    Answer: (D) 40 m

    R = u² sin2θ / g = 400 × sin90° / 10 = 40 m — the maximum range at this speed.

  4. What stays constant in uniform circular motion?
    1. velocity
    2. speed
    3. acceleration
    4. momentum
    Show answer

    Answer: (B) speed

    Speed stays constant, but because the direction changes every moment, the directions of velocity, momentum and acceleration keep changing.

  5. Why is the outer edge of a road raised at a turn?
    1. for beauty
    2. to drain water
    3. to get the centripetal force
    4. to increase friction
    Show answer

    Answer: (C) to get the centripetal force

    On a banked road the horizontal part of the normal reaction (N sinθ) gives the needed centripetal force, so the vehicle does not skid.

  6. Which force is called a pseudo force?
    1. centrifugal force
    2. centripetal force
    3. gravitational force
    4. frictional force
    Show answer

    Answer: (A) centrifugal force

    Centrifugal force is not a real force — it is felt in a rotating frame and has no reaction.

  7. Passengers lean back when a bus starts suddenly. This is an example of —
    1. inertia of motion
    2. inertia of rest
    3. inertia of direction
    4. conservation of momentum
    Show answer

    Answer: (B) inertia of rest

    The feet move with the bus while the upper body wants to stay at rest — this is inertia of rest.

  8. A fielder pulls his hands back while catching a ball so that —
    1. momentum increases
    2. friction increases
    3. the ball stops faster
    4. contact time increases and force decreases
    Show answer

    Answer: (D) contact time increases and force decreases

    Impulse FΔt = Δp is fixed; increasing the time Δt reduces the force F on the hands.

  9. A rocket works on the principle of —
    1. conservation of momentum
    2. conservation of energy
    3. Bernoulli’s principle
    4. Pascal’s law
    Show answer

    Answer: (A) conservation of momentum

    A rocket throws gas backward at high speed and, by conservation of momentum (Newton’s third law), moves forward — even in vacuum.

  10. A 20 N horizontal force acts on a 10 kg box (μₛ = 0.5, g = 10). How much is the friction?
    1. 50 N
    2. 0 N
    3. 20 N
    4. 100 N
    Show answer

    Answer: (C) 20 N

    Limiting friction is 50 N, but the applied force is only 20 N; the box does not move and static friction is just as much (20 N).

  1. Why is pulling a lawn roller easier than pushing it?
    1. pushing makes friction zero
    2. pulling reduces the mass
    3. pulling reduces the normal reaction
    4. both are equal
    Show answer

    Answer: (C) pulling reduces the normal reaction

    While pulling, the vertical part of the force acts upward, which reduces N and so the friction; pushing increases N.

  2. In the northern hemisphere, cyclones spin —
    1. anticlockwise
    2. clockwise
    3. in a straight line
    4. in no fixed direction
    Show answer

    Answer: (A) anticlockwise

    The Coriolis force bends winds to the right in the northern hemisphere, so cyclones spin anticlockwise.

  3. A nutcracker is which class of lever?
    1. first
    2. not a lever
    3. third
    4. second
    Show answer

    Answer: (D) second

    In a nutcracker the fulcrum is at one end, the effort at the other end and the load (the nut) in the middle — second class.

  4. Which of these levers always has a mechanical advantage less than 1?
    1. scissors
    2. tongs
    3. wheelbarrow
    4. see-saw
    Show answer

    Answer: (B) tongs

    Tongs are a third-class lever (effort in the middle), whose effort arm is always shorter than the load arm.

  5. The work done against gravity by a porter walking on level road with a load on his head is —
    1. zero
    2. negative
    3. positive
    4. infinite
    Show answer

    Answer: (A) zero

    Gravity is vertical and the displacement is horizontal — they are perpendicular, so W = Fs cos90° = 0.

  6. If the momentum of a body is doubled, its kinetic energy becomes —
    1. double
    2. half
    3. four times
    4. the same
    Show answer

    Answer: (C) four times

    K = p²/2m; doubling p makes K four times.

  7. 1 kilowatt-hour (kWh) is a unit of —
    1. power
    2. energy
    3. force
    4. momentum
    Show answer

    Answer: (B) energy

    kWh = 1000 W × 3600 s = 3.6 × 10⁶ J — a unit of energy, called a "unit" in the electricity bill.

  8. In which collision is kinetic energy not conserved?
    1. Elastic collision
    2. It is conserved in neither
    3. It is conserved in both
    4. Inelastic collision
    Show answer

    Answer: (D) Inelastic collision

    In an inelastic collision momentum is saved, but some kinetic energy turns into heat or sound.

  9. Why are passengers not allowed to stand on the upper deck of a double-decker bus?
    1. weight increases
    2. the bus slows down
    3. friction falls
    4. the centre of gravity rises and the bus becomes unstable
    Show answer

    Answer: (D) the centre of gravity rises and the bus becomes unstable

    More weight on top raises the centre of gravity, and the danger of the bus toppling at a turn increases.

  10. A ballet dancer spins faster when she pulls her arms in. Reason?
    1. conservation of energy
    2. conservation of angular momentum
    3. conservation of linear momentum
    4. less friction
    Show answer

    Answer: (B) conservation of angular momentum

    Iω stays constant; pulling the arms in reduces I, so ω increases.

  1. A solid sphere, a disc and a ring of equal mass and radius roll down the same slope. Which reaches the bottom first?
    1. ring
    2. disc
    3. solid sphere
    4. all together
    Show answer

    Answer: (C) solid sphere

    The solid sphere has the smallest k²/R² (2/5), so less of its energy goes into turning and it is fastest; the ring is last.

  2. By Kepler’s law, what is the relation between period and distance?
    1. T² ∝ a³
    2. T² ∝ a
    3. T ∝ a³
    4. T ∝ a
    Show answer

    Answer: (A) T² ∝ a³

    Third law: the square of the period is proportional to the cube of the semi-major axis of the orbit.

  3. Where on Earth is the value of g greatest?
    1. at the equator
    2. at the poles
    3. at the centre of the Earth
    4. on the Tropic of Cancer
    Show answer

    Answer: (B) at the poles

    At the poles the radius is smallest and rotation has no effect, so g is greatest (≈ 9.83 m/s²).

  4. What is the escape velocity from the Earth’s surface?
    1. 7.9 km/s
    2. 42 km/s
    3. 3.07 km/s
    4. 11.2 km/s
    Show answer

    Answer: (D) 11.2 km/s

    vₑ = √(2gR) ≈ 11.2 km/s. 7.9 km/s is the orbital velocity near the surface and 3.07 km/s is the speed of a geostationary satellite.

  5. At what height is a geostationary satellite kept?
    1. About 36,000 km
    2. About 8,000 km
    3. About 800 km
    4. About 3,60,000 km
    Show answer

    Answer: (A) About 36,000 km

    A geostationary satellite is kept about 35,786 km (≈ 36,000 km) above the equator; its period is 24 hours.

  6. In which condition do we feel weightlessness?
    1. Lift at rest
    2. Lift accelerating upward
    3. Lift’s cable snaps
    4. Lift moving down at uniform speed
    Show answer

    Answer: (C) Lift’s cable snaps

    When the cable snaps, the lift and the person both fall freely; the floor gives no reaction, so the apparent weight is zero.

More chapters in this subject