Board Boosters
The questions your board exam loves to ask
800 most-asked Class 11 & 12 (+1 / +2) questions across Physics, Chemistry, Maths and Biology — each with a model answer and the exact marking-scheme points examiners reward. Revise smart, walk in calm.
PhysicsClass 113 marksmedium
Units and Measurements
Using Newton's law of gravitation, derive the dimensional formula of the universal gravitational constant G.
Reveal model answer + marking pointsHide answer▾
From F = G M m / r^2, we get G = F r^2 / (M m). Dimensions: [G] = ([F][r^2]) / ([M][m]) = (M L T^-2 * L^2) / (M * M) = M^-1 L^3 T^-2.
G = F r^2 / (M m)
Marking-scheme points
- ✓Rearrange F = GMm/r^2 for G
- ✓Substitute [F] = M L T^-2
- ✓Final: [G] = M^-1 L^3 T^-2
PhysicsClass 113 markseasy
Motion in a Straight Line
A ball is thrown vertically upward with a speed of 20 m/s. Taking g = 10 m/s^2, find (a) the maximum height reached and (b) the total time before it returns to the thrower's hand.
Reveal model answer + marking pointsHide answer▾
At maximum height the velocity is zero. (a) h = u^2 / (2g) = (20)^2 / (2*10) = 400/20 = 20 m. (b) Time of flight T = 2u/g = (2*20)/10 = 4 s.
h = u^2/2g ; T = 2u/g
Marking-scheme points
- ✓At top, v = 0
- ✓h = u^2/2g = 20 m
- ✓T = 2u/g = 4 s
PhysicsClass 113 marksmedium
Laws of Motion
A 2 kg block resting on a rough horizontal surface (coefficient of friction 0.2) is pulled by a horizontal force of 10 N. Taking g = 10 m/s^2, find its acceleration.
Reveal model answer + marking pointsHide answer▾
Force of friction f = mu * m g = 0.2 * 2 * 10 = 4 N. Net force = applied - friction = 10 - 4 = 6 N. Acceleration a = net force / mass = 6 / 2 = 3 m/s^2.
f = mu m g ; a = (F - f)/m
Marking-scheme points
- ✓f = mu m g = 4 N
- ✓Net force = 10 - 4 = 6 N
- ✓a = F/m = 3 m/s^2
PhysicsClass 113 markseasy
Work, Energy and Power
A body of mass 5 kg falls freely from a height of 20 m. Using g = 10 m/s^2, find its kinetic energy just before it strikes the ground.
🔒 Model answer + marking pointsUnlock with Premium →PhysicsClass 113 marksmedium
System of Particles and Rotational Motion
State the theorem of parallel axes and use it to find the moment of inertia of a uniform rod (mass M, length L) about an axis through one end, perpendicular to the rod.
🔒 Model answer + marking pointsUnlock with Premium →PhysicsClass 113 marksmedium
Gravitation
Calculate the escape velocity from the surface of the Earth. Take g = 9.8 m/s^2 and R = 6.4 x 10^6 m.
🔒 Model answer + marking pointsUnlock with Premium →PhysicsClass 113 marksmedium
Thermodynamics
Distinguish between an isothermal process and an adiabatic process (any three points).
🔒 Model answer + marking pointsUnlock with Premium →PhysicsClass 113 marksmedium
Kinetic Theory
Calculate the root-mean-square speed of oxygen molecules at 300 K. Take molar mass M = 32 g/mol = 0.032 kg/mol and R = 8.31 J/mol/K.
🔒 Model answer + marking pointsUnlock with Premium →PhysicsClass 113 marksmedium
Oscillations
Show that the oscillation of a simple pendulum is simple harmonic for small angles, and derive its time period.
🔒 Model answer + marking pointsUnlock with Premium →PhysicsClass 113 marksmedium
Units and Measurements
The percentage errors in measuring quantities A and B are 2% and 3% respectively. Find the maximum percentage error in the quantity P = A * B^2.
🔒 Model answer + marking pointsUnlock with Premium →PhysicsClass 113 marksmedium
Motion in a Straight Line
Using a velocity-time graph, derive the equation s = u t + (1/2) a t^2 for uniformly accelerated motion.
🔒 Model answer + marking pointsUnlock with Premium →PhysicsClass 113 marksmedium
Motion in a Straight Line
A car moving at 20 m/s is brought to rest with a uniform deceleration of 5 m/s^2. Find the stopping distance.
🔒 Model answer + marking pointsUnlock with Premium →PhysicsClass 113 marksmedium
Motion in a Plane
State the parallelogram law of vector addition and write the expression for the magnitude of the resultant of two vectors P and Q inclined at an angle theta.
🔒 Model answer + marking pointsUnlock with Premium →PhysicsClass 113 marksmedium
Motion in a Plane
A ball is projected with a speed of 30 m/s at 30 degrees to the horizontal. Find its horizontal range. Take g = 10 m/s^2.
🔒 Model answer + marking pointsUnlock with Premium →PhysicsClass 113 marksmedium
Laws of Motion
A gun of mass 4 kg fires a bullet of mass 20 g with a muzzle speed of 400 m/s. Find the recoil velocity of the gun.
🔒 Model answer + marking pointsUnlock with Premium →PhysicsClass 113 marksmedium
Laws of Motion
A block slides down a smooth inclined plane of inclination 30 degrees. Find its acceleration. Take g = 10 m/s^2.
🔒 Model answer + marking pointsUnlock with Premium →PhysicsClass 113 marksmedium
Work, Energy and Power
A pump lifts 100 kg of water to a height of 10 m in 5 s. Calculate the power of the pump. Take g = 10 m/s^2.
🔒 Model answer + marking pointsUnlock with Premium →PhysicsClass 113 marksmedium
System of Particles and Rotational Motion
State the law of conservation of angular momentum and explain why a spinning skater speeds up on pulling in the arms.
🔒 Model answer + marking pointsUnlock with Premium →PhysicsClass 113 marksmedium
System of Particles and Rotational Motion
State the theorem of perpendicular axes and use it to find the moment of inertia of a ring (mass M, radius R) about a diameter.
🔒 Model answer + marking pointsUnlock with Premium →PhysicsClass 113 marksmedium
Gravitation
State Kepler's three laws of planetary motion.
🔒 Model answer + marking pointsUnlock with Premium →You are more ready than you feel.
One question at a time is how every topper started. Bookmark this, revise a few each day, and watch the fear shrink. And if a friend is stressing about boards — send this their way. You both win.