# Very Important Long Questions Collection â€“ All Unit | Physics Class 11

## HSEB Exam | Questions Collection

Very Important Long Questions Collection

For: Science | Physics Class 11

From: All Unit

We have listed some very Important Questions. The repeating frequency of this questions are Comparatively High. This questions are asked on lots of previous papers.

Disclaimer: This questions are neither guessed nor we guarantee the possibility in the coming exam. This questions are often repeated in the previous exams.

**Unit 1: Mechanics**

- State the parallelogram law of vector addition. Derive the expression for the magnitude and direction of the resultant of two vectors inclined at an angle ? from each other. [2069]
- State triangle law of vector addition. Obtain an expression for the resultant of two vectors P and Q inclined an angle ?. [2066]
- Derive expression for maximum height, range of projectile fired at angle ? with horizontal. [2067]
- State the principle of conservation of linear momentum. How does the Newton?s third law of motion lead to the principle of conservation of linear momentum? [2069]
- State Newton?s laws of motion. Show that Newton?s first law of motion defines force and second law of motion defines the unit of force. [2064]
- What is the angle of repose? Show that when a body just begins to slide down on an inclined plane, the coefficient of friction is equal to the tangent of inclination of the plane. [2063]
- What do you understand by friction? Explain its cause. Show that the coefficient of static friction is equal to the angle of repose. [2062]
- What is the principle of conservation of energy? Show that total mechanical energy of conserved when it moves under the action of gravitational field. [2069]
- Define work. Derive an expression to calculate work done by a variable force. [2067]
- What are elastic and inelastic collision? Give an example of each. Write the energy and momentum equations for an inelastic collision. [2059]
- Define centripetal force. Calculate the force acting on a body moving with uniform speed along circular path. [2069]
- What is conical pendulum? Show that the period of oscillation of this pendulum is given by: T = 2? (lcos?/g)
^{1/2}[2066] - What is escape velocity? Derive expression for it. [2069]
- What is acceleration due to gravity? Explain how it varies with the altitude. [2058]
- What is satellite? Calculate the orbital velocity of of an artificial satellite. [2056]
- State principle of moments. Explain how you verify the principle of moment in your laboratory. [2059]
- Define moment of inertia and angular momentum. Establish a relation between them. [2068]
- What is meant by a couple? Derive an expression for the work done by a couple. [2066]
- Define moment of inertia. How is it related with rotation kinetic energy of a body? [2057]
- What do you mean by elastic limit? Derive an expression for the energy stored in stretched wire. [2069]
- Define stress and strain. Derive an expression for energy stored in a stretched wire. [2068]
- State Hook?s Law and describes different types of modulus of elasticity. [2066]
- Define elastic limit and Young?s modulus of elasticity. Explain how you would determine Young?s modulus for a material in the form of a wire. [2060]
- What is Poisson?s ratio? Derive an expression for the energy stored in a stretched wire? [2057]
- Define Simple harmonic motion and obtain an expression of time period of a simple pendulum. [2069]
- What is simple pendulum? Show that motion of the bob of the simple pendulum is simple harmonic. Obtain an expression for its frequency. [2069]
- Explain, with necessary theory, the capillary tube method for the measurement of surface tension of a liquid. [2068]
- What is capillarity? Deduce an expression for the rise of a liquid in capillary tube. [2067]
- Derive Newton?s formula for viscous force. Define coefficient of viscosity. Calculate its dimensions. [2068]
- Derive an expression for terminal velocity of a small spherical ball of radius ?a? dropped gently in a viscous liquid of density p and coefficient of viscosity ?. [2066]
- Derive Bernoulli?s equation form the work energy theorem. Explain why the equation valid only for steady, non-viscous and incompressible fluid. [2059]

** Unit 2: Heat and Thermodynamics**

- Define linear and cubical expansivities of solids. Derive an expression for the variation in density of a solid when its temperature is raised from ?°1C to ?°2C. [2069]
- Define coefficient of linear expansion. Obtain the relation between ? and ?. [2066]
- Define linear, superficial, and cubical expansivities. Show that ? = 2? where ? and ? are linear and superficial expansivities. [2060]
- Obtain an expression for the change in density of a gas due to the thermal expansion. [2051]
- State and explain Newton?s law of cooling and derive the expression for the specific heat of the liquid. [2069]
- Define latent head of fusion of ice. Describe the method for the measurement of it in the laboratory. [2068]
- State Charle?s law of gases. Derive the ideal gas equation PV = nRT. Where symbol have usual meaning. [2069]
- Use the kinetic theory of gases to derive an expression for the pressure exerted by a gas on the walls of its container. [2069]
- State Boyle?s law and Charle?s law and hence obtain the relationship for the combined gas law. [2062]
- Define thermal conductivity. Describe Searle?s method of determination of thermal conductivity of good conductor. [2069]
- What is a black body? Derive Stefan?s law of black body radiation. [2058]
- What do you mean by isothermal process? Obtain an expression for the work done by an ideal gas in the isothermal process. [2069]
- Define tow specific heat capacity of the gas. Show that for an ideal gas Cp ? Cv = R. [2069]
- Define adiabatic process in thermodynamics. Show that: PVy = constant. Where symbols have their usual meanings. [2066]
- State and explain the first law of thermodynamics and use it to derive the relation, PVy = constant where the symbols have their usual meanings. [2064]
- Describe the working of petrol engine with the help of P-V diagram. [2069]
- Describe the working of carnot?s engine with the help of its p-v diagram. [2069]
- What is heat engine? Calculate the thermal efficiency of a heat engine. [2068]
- State and explain the second law of thermodynamics. [2063]

**Unit 3: Geometric Optics**

- Point out the difference between real image and virtual image. Obtain a realtion connecting the objects distance, image distance and focal length of concave mirror. [2069]
- What do you mean by principle forms of a convex mirror? Prove mirror formula for a convex mirror and also show that m = v/u for the same mirror. [2064]
- What is lateral shift? Derive an expression for it due to a parallel edged glass slab. [2067]
- What is the deviation of light? Show that deviation produced by a small angled prism is independent of the angle of incidence. [2069]
- Derive an expression for lens maker?s formula. [2069]
- Define radius of curvature of a lens. Derive Lens maker?s formula. [2068]
- Define principle focus. Derive the lens formula for the concave lens and show that m = v/u for the same lens. [2065]
- What is chromatic aberration? Show that the chromatic aberration is the product of dispersive power and mean focal length of a lens. [2069]
- With the help of a labeled diagram. Explain the principle and working of a compound microscope. Derive an expression for the magnifying power. [2069]
- What is long sightedness? Discuss the possible causes of long sightedness. Explain, how this deflect can be remedied. [2069]

**Unit 4: Electrostatics**

- State Gauss Theorem. Use this theorem to find the electric field intensity due to a plane charged conductor. [2069]
- Define electric potential. Derive an expression for the potential due to a point charge at any point in space. [2069]
- How can a number of capacitor be connected to increase and decrease the effective capacitor? Find the respective expression for the effective capacitance in each case. [2069]
- Find the equivalent capacitance of two capacitors when they are connected. (i) in series and (ii) in parallel. [2069]
- What is capacitor? Find the energy stored in a charged capacitor. [2067]