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 112 markseasy
Mechanical Properties of Solids
Name the three moduli of elasticity and state what each measures.
Reveal model answer + marking pointsHide answer▾
Young's modulus (Y) measures resistance to change in length (longitudinal stress/strain). Bulk modulus (B) measures resistance to change in volume (volume stress/strain) under uniform pressure. Shear (rigidity) modulus (G) measures resistance to change in shape (shearing stress/strain).
Marking-scheme points
- ✓Young's Y: change in length
- ✓Bulk B: change in volume
- ✓Shear/rigidity G: change in shape
PhysicsClass 112 marksmedium
Thermal Properties of Matter
State Stefan's law and Wien's displacement law of black-body radiation.
Reveal model answer + marking pointsHide answer▾
Stefan's (Stefan-Boltzmann) law: the total energy radiated per unit area per unit time by a black body is proportional to the fourth power of its absolute temperature, E = sigma T^4. Wien's displacement law: the wavelength at which the emission is maximum is inversely proportional to the absolute temperature, lambda_max * T = constant (= 2.9 x 10^-3 m K).
E = sigma T^4 ; lambda_max T = b
Marking-scheme points
- ✓Stefan: E = sigma T^4
- ✓Wien: lambda_max T = constant
- ✓Hotter body -> shorter peak wavelength
PhysicsClass 112 marksmedium
Kinetic Theory
Define mean free path of a gas molecule. State two factors it depends on.
Reveal model answer + marking pointsHide answer▾
The mean free path is the average distance a gas molecule travels between two successive collisions. It increases when the number density of molecules is low and when the molecular diameter is small; that is, it is inversely proportional to the number density and to the square of the molecular diameter.
lambda = 1 / (sqrt(2) pi d^2 n)
Marking-scheme points
- ✓Average distance between collisions
- ✓Inversely proportional to number density
- ✓Inversely proportional to (diameter)^2
PhysicsClass 112 markseasy
System of Particles and Rotational Motion
Define the centre of mass of a system of particles. Write its position for a two-particle system.
🔒 Model answer + marking pointsUnlock with Premium →PhysicsClass 112 marksmedium
Gravitation
How does the acceleration due to gravity vary with depth below the Earth's surface? What is its value at the centre?
🔒 Model answer + marking pointsUnlock with Premium →PhysicsClass 112 markseasy
Motion in a Plane
What is meant by resolution of a vector? Write the rectangular components of a vector A making angle theta with the x-axis.
🔒 Model answer + marking pointsUnlock with Premium →PhysicsClass 112 marksmedium
Thermodynamics
What is a quasi-static process? Why is it important?
🔒 Model answer + marking pointsUnlock with Premium →PhysicsClass 112 markseasy
Gravitation
State Newton's universal law of gravitation and write its mathematical form.
🔒 Model answer + marking pointsUnlock with Premium →ChemistryClass 112 markseasy
Some Basic Concepts of Chemistry
State the law of conservation of mass and the law of definite proportions.
🔒 Model answer + marking pointsUnlock with Premium →ChemistryClass 112 markseasy
Some Basic Concepts of Chemistry
Calculate the number of moles present in 11 g of carbon dioxide (CO2).
🔒 Model answer + marking pointsUnlock with Premium →ChemistryClass 112 markseasy
Some Basic Concepts of Chemistry
Define one mole and state the value of Avogadro's number.
🔒 Model answer + marking pointsUnlock with Premium →ChemistryClass 112 markseasy
Some Basic Concepts of Chemistry
Define molarity and molality. State their units.
🔒 Model answer + marking pointsUnlock with Premium →ChemistryClass 112 marksmedium
Some Basic Concepts of Chemistry
Define mole fraction and mass percent of a component in a solution.
🔒 Model answer + marking pointsUnlock with Premium →ChemistryClass 112 marksmedium
Structure of Atom
Calculate the energy of a photon of light of wavelength 4000 Angstrom. (h = 6.626 x 10^-34 J s, c = 3 x 10^8 m/s)
🔒 Model answer + marking pointsUnlock with Premium →ChemistryClass 112 markseasy
Structure of Atom
State Heisenberg's uncertainty principle and give its mathematical form.
🔒 Model answer + marking pointsUnlock with Premium →ChemistryClass 112 marksmedium
Structure of Atom
Calculate the wave number of the spectral line when an electron in a hydrogen atom jumps from n = 3 to n = 2. (Rydberg constant R = 1.097 x 10^7 m^-1)
🔒 Model answer + marking pointsUnlock with Premium →ChemistryClass 112 markseasy
Structure of Atom
State Pauli's exclusion principle and Hund's rule of maximum multiplicity.
🔒 Model answer + marking pointsUnlock with Premium →ChemistryClass 112 markseasy
Structure of Atom
State the Aufbau principle and the (n + l) rule for filling of orbitals.
🔒 Model answer + marking pointsUnlock with Premium →ChemistryClass 112 markseasy
Classification of Elements and Periodicity
State the modern periodic law. How does it differ from Mendeleev's periodic law?
🔒 Model answer + marking pointsUnlock with Premium →ChemistryClass 112 marksmedium
Classification of Elements and Periodicity
Why is the first ionization enthalpy of nitrogen greater than that of oxygen?
🔒 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.