Class 11 Physics Most Important Questions

Mechanics

Q1. What is gravitational potential energy? Obtain an expression for the gravitational potential energy of a body at a distance $r$ from the centre of the Earth.

Q2. Define centripetal force. Show that the acceleration of a body moving in a circular path of radius $r$ with uniform speed $v$ is $\frac{v^2}{r}$, directed towards the centre.

Q3. Motion of a car moving on a circular banked track. (Numerical)

Q4. State the triangle law of vector addition. Obtain an expression for the resultant of two vectors $F$ and $Q$ inclined at an angle $\theta$.

Q5. What do you mean by the banking of a curved path? Derive an expression for the banking angle.

Q6. What is the principle of conservation of energy? Show that total mechanical energy is conserved under a gravitational field.

Q7. Define escape velocity. Derive an expression for the escape velocity from Earth’s surface.

Q8. What is a conical pendulum? Show that its period is $T = 2\pi \sqrt{\frac{l \cos \theta}{g}}$.

Q9. Derive Newton’s First and Third Laws of Motion from Newton’s Second Law.

Q10. State and prove the conservation of mechanical energy.

Q11. Describe the motion of a bicycle on a curved road.

Q12. What is angle of repose? Show that coefficient of friction equals tangent of the angle of inclination when the body just begins to slide.

Q13. Derive the expression for variation of acceleration due to gravity with altitude.

Q14. State and prove the principle of conservation of linear momentum.

Q15. Define work. Derive expression for work done by a variable force.

Q16. What is elastic collision? Prove that colliding bodies exchange velocities in a 1D elastic collision.

Q17. Explain the concept of a geostationary satellite. Find expression for total energy of Moon revolving around Earth.

Q18. What is a parking orbit? Derive expressions for orbital velocity and time period of a satellite.

Q19. A projectile is fired with velocity $v$ at angle $\theta$. Derive expressions for:

• (a) Maximum height

• (b) Time of flight

• (c) Horizontal range
  Also, find condition for maximum horizontal range.

Q20. State parallelogram law of vector addition. Derive magnitude and direction of resultant.

Q21. Define projectile. Show that the path of a horizontally projected object is parabolic. At what angle does it hit the ground?

Q22. State the law of conservation of momentum.

Q23. Gravitational potential due to point mass: definition, types, and uses.

Q24. State Hooke’s Law.

Q25. Describe method to determine Young's modulus of elasticity.

Q26. Define escape velocity, orbital velocity, and time period of satellite from Earth.

Q27. Derive the time period of a conical pendulum.

Q28. Laws of vector addition: Triangle and Parallelogram law.

Q29. Projectile motion: Show that its trajectory is parabolic.

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Heat

Q1. Define linear and cubical expansivity. Derive expression for variation in density from $\theta_1^\circ C$ to $\theta_2^\circ C$.

Q2. Does coefficient of linear expansion depend on length? Explain.

Q3. Define linear and cubical expansion coefficients. Derive relation between them.

Q4. Define real and apparent expansion of liquid. Derive the relation.

Q5. Relation between $\alpha$, $\beta$, and $\gamma$.

Q6. State and explain Newton’s law of cooling. Derive expression for specific heat using cooling.

Q7. Define thermal capacity. Describe method of mixtures to determine specific heat.

Q8. Define linear and superficial expansivity. Show that $\beta = 2\alpha$.

Q9. State the second law of thermodynamics.

Q10. Describe method to determine linear expansivity. Can cubical expansivity be derived from it?

Q11. Define thermal conductivity. Describe Searle’s method to determine it.

Q12. What is latent heat of vaporization of water? Derive expression for its determination.

Q13. Newton’s law of cooling. (Repetition of Q6)

Q14. Differentiate between real and apparent expansion. Describe method to determine real expansion.

Q15. Define latent heat of fusion of ice. Describe method to measure it.

Q16. Define thermal conductivity.

Q17. What is a perfectly black body? State and explain Stefan’s law.

Q18. Define Boyle’s and Charles’s law. Prove $PV = nRT$.

Q19. From kinetic theory, derive: $P = \frac{1}{3} \rho \bar{c}^2$

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Ray Optics

Q1. Define achromatism. Derive condition for achromatic combination of two thin lenses in contact.

Q2. Define critical angle and total internal reflection.

Q3. What is chromatic aberration? Show that it equals dispersive power × focal length of mean light.

Q4. Derive the lens maker's formula. What is the unit of power of a lens?

Q5. Define lateral shift. Derive expression and variation with angle of incidence.

Q6. Applications of curved mirrors.

Q7. What is minimum deviation? Show it is independent of angle of incidence for small-angle prism.

Q8. Lateral shift. (Repetition of Q5)

Q9. Derive expression for focal length of two coaxial thin lenses.

Q10. For a prism, show:

$$m = \frac{\sin \left( \frac{A + D_m}{2} \right)}{\sin \left( \frac{A}{2} \right)}$$

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Electrostatics

Q1. State Gauss's Law. Use it to find the electric field due to an infinite thin metallic sheet.

Q2. Define potential gradient. Derive relation between electric field and potential gradient.

Q3. What is electrostatic induction? How to charge a sphere positively using it?

Q4. Define electric potential. Derive potential difference and due to point charge.

Q5. Define capacitance. Derive capacitance of a parallel plate capacitor.

Q6. Electric potential due to point charge. (Repetition of Q4)

Q7. What is a capacitor? Find energy stored in a charged capacitor.

Q8. State Gauss’s Theorem. Use it to find field of a hollow charged spherical conductor.

Q9. Define capacitance. Derive equivalent capacitance in:

• (i) Series

• (ii) Parallel

Q10. State Gauss’s Law. Apply it to a linearly charged body for field.

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Modern Physics

Q1. Quarks have spin 1/2. Explain how the proton also has spin 1/2.

Q2. The mass of ${}^{239}\text{Pu}$ is 238.9984. Find binding energy per nucleon.

Q3. Write quark composition of a proton.