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 markshard
Laws of Motion
Why are roads banked at curves? Write the expression for the ideal speed on a frictionless banked road of angle theta and radius r.
Reveal model answer + marking pointsHide answer▾
Roads are banked at curves so that the horizontal component of the normal reaction provides the centripetal force needed to turn, reducing reliance on friction and the risk of skidding. On a frictionless banked road, the ideal (safe) speed is v = sqrt(r g tan(theta)).
v = sqrt(r g tan(theta))
Marking-scheme points
- ✓Banking supplies centripetal force via normal reaction
- ✓Reduces dependence on friction
- ✓v = sqrt(r g tan theta)
PhysicsClass 113 markshard
Mechanical Properties of Fluids
Write the expression for the terminal velocity of a small sphere falling through a viscous fluid and name the quantities.
Reveal model answer + marking pointsHide answer▾
v_t = (2 r^2 (rho - sigma) g) / (9 eta), where r is the radius of the sphere, rho its density, sigma the density of the fluid, g the acceleration due to gravity and eta the coefficient of viscosity. It is obtained by balancing the weight against the buoyant force and the viscous (Stokes) drag.
v_t = 2 r^2 (rho - sigma) g / (9 eta)
Marking-scheme points
- ✓v_t = 2 r^2 (rho - sigma) g / (9 eta)
- ✓From weight = buoyancy + viscous drag
- ✓v_t proportional to r^2
PhysicsClass 113 marksmedium
Thermodynamics
What is a refrigerator in thermodynamic terms? Write the expression for its coefficient of performance.
Reveal model answer + marking pointsHide answer▾
A refrigerator is a heat engine working in reverse: it uses external work W to extract heat Q_c from a cold body and reject a larger heat Q_h to the hot surroundings, so Q_h = Q_c + W. Its coefficient of performance is beta = Q_c / W = Q_c / (Q_h - Q_c). A good refrigerator has a high beta.
beta = Q_c / (Q_h - Q_c)
Marking-scheme points
- ✓Reverse heat engine, uses work W
- ✓Q_h = Q_c + W
- ✓beta = Q_c / W = Q_c/(Q_h - Q_c)
PhysicsClass 113 marksmedium
Oscillations
For a particle in SHM given by x = A sin(omega t), write the expressions for its velocity and acceleration, and state where each is maximum.
🔒 Model answer + marking pointsUnlock with Premium →PhysicsClass 113 marksmedium
Waves
Write Newton's formula for the speed of sound in a gas and state Laplace's correction to it.
🔒 Model answer + marking pointsUnlock with Premium →PhysicsClass 113 marksmedium
Laws of Motion
A person of mass 50 kg stands in a lift. Find the apparent weight when the lift accelerates upward at 2 m/s^2. Take g = 10 m/s^2.
🔒 Model answer + marking pointsUnlock with Premium →PhysicsClass 113 markshard
Work, Energy and Power
Write the condition (minimum speed) for a body to just complete a vertical circle of radius r at the highest point, and the corresponding minimum speed at the lowest point.
🔒 Model answer + marking pointsUnlock with Premium →PhysicsClass 113 marksmedium
Waves
Compare the harmonics produced in an open organ pipe and a closed organ pipe.
🔒 Model answer + marking pointsUnlock with Premium →PhysicsClass 113 marksmedium
Motion in a Straight Line
A body starts from rest and moves with a uniform acceleration of 2 m/s^2. Find the distance travelled by it during the 5th second.
🔒 Model answer + marking pointsUnlock with Premium →ChemistryClass 113 marksmedium
Some Basic Concepts of Chemistry
How many molecules and how many atoms are present in 0.25 mol of CO2? (Avogadro number = 6.022 x 10^23)
🔒 Model answer + marking pointsUnlock with Premium →ChemistryClass 113 markshard
Some Basic Concepts of Chemistry
A compound contains 24.27% carbon, 4.07% hydrogen and 71.65% chlorine by mass. Its molar mass is 98.96 g/mol. Find its empirical and molecular formula.
🔒 Model answer + marking pointsUnlock with Premium →ChemistryClass 113 marksmedium
Some Basic Concepts of Chemistry
Calculate the molarity of a solution prepared by dissolving 5 g of NaOH in enough water to make 450 mL of solution.
🔒 Model answer + marking pointsUnlock with Premium →ChemistryClass 113 markshard
Some Basic Concepts of Chemistry
3.0 g of H2 reacts with 29 g of O2 to form water (2H2 + O2 -> 2H2O). Identify the limiting reagent and calculate the mass of water formed.
🔒 Model answer + marking pointsUnlock with Premium →ChemistryClass 113 marksmedium
Structure of Atom
State the main postulates of Bohr's model of the hydrogen atom.
🔒 Model answer + marking pointsUnlock with Premium →ChemistryClass 113 marksmedium
Structure of Atom
The radius of the first Bohr orbit of hydrogen is 0.529 Angstrom. Calculate the radius of the third orbit.
🔒 Model answer + marking pointsUnlock with Premium →ChemistryClass 113 marksmedium
Structure of Atom
Calculate the de Broglie wavelength of an electron moving with a velocity of 2.05 x 10^7 m/s. (mass of electron = 9.1 x 10^-31 kg, h = 6.626 x 10^-34 J s)
🔒 Model answer + marking pointsUnlock with Premium →ChemistryClass 113 marksmedium
Structure of Atom
What are the four quantum numbers? State what each one describes.
🔒 Model answer + marking pointsUnlock with Premium →ChemistryClass 113 marksmedium
Structure of Atom
Write the electronic configurations of chromium (Z = 24) and copper (Z = 29). Explain why they are exceptions to the expected order.
🔒 Model answer + marking pointsUnlock with Premium →ChemistryClass 113 marksmedium
Classification of Elements and Periodicity
How does atomic radius vary across a period and down a group? Give reasons.
🔒 Model answer + marking pointsUnlock with Premium →ChemistryClass 113 marksmedium
Classification of Elements and Periodicity
Define ionization enthalpy. Explain its trend across a period and down a group.
🔒 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.