HSEB Exam | Questions Collection
Very Important Long Questions Collection
For: Science | Physics Class 12
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 exam only.
Unit One: Wave and Optics
- What are stationary waves? Derive an equation for such a wave. [2060]
- What the principle of superposition is as applied to wave motion? Discuss the result of superposing two waves of equal amplitude and same frequency travelling in opposite direction. [2068]
- How is a progressive wave different from a stationary wave? Derive a progressive wave equation. [2070 ‘D’]
- What is Newton’s formula for the velocity of sound? What correction was made by Laplace? [2053]
- Describe the various modes of vibrations of the air column in an organ pipe. [2054]
- What is Doppler’s effect? Derive an expression for the apparent frequency received by a stationary observer when a source is moving away from him. [2057]
Unit Two: Physical Optics
- State and explain Huygens’s principle to show that a plane wave front incident obliquely on a plane mirror is reflected as a plane wave front so that the angle of incidence is equal to the angle of reflection. [2060, 2068]
- Define Michelson’s method to determine the speed of light. Write advantages of this method over Foucault’s method. [2067]
- What are coherent source? Prove analytically that the bright and dark fringes in young’s double slit experiment are equally spaced. [2060]
- Describe Young’s double slit interference experiment to determine the wavelength of the source of light. [2069]
- What do you mean by polarization of light? Show that tanθp = np where θp is the angle of polarization and Ƞ is the refractive index of the transparent medium. [2059]
Unit Three: Electricity and Magnetism
- What do you mean by a shunt? Describe its use in converting a galvanometer into an ammeter. [2057]
- What is drift velocity of an electron? Derive a relation between the current through a metallic conductor and the drift velocity in terms of the number of free electrons per unit volume of the conductor. [2059]
- State and explain Ohm’s law. [2064]
- What is potentiometer? Explain how do you compare emf of two cells using potentiontiometr. [2058]
- What is a Wheatstone bridge? Obtain the balanced condition for the bridge. Explain how resistance can be measured by a meter bridge. [2068]
- Explain, what do you mean by seebeck effect? How does thermoelectric emf vary with the temperature? [2057]
- State and explain Faraday’s laws of electrolysis. Hence. Define Faraday’s constant. [2058]
- Define the formula for the magnetic field at the centre of a circular coil carrying current. Explain why the magnetic field at the centre of the coil disappears when the circular coil is made infinitely large. [2059]
- Derive an expression for the torque experienced by a current carrying rectangular coil placed in a uniform magnetic field and hence define magnetic dipole moment of the coil. [2060]
- Derive an expression of force per unit length between two parallel conductors separated by a distance ‘r’ and carrying currents I1 and I2 in the same direction. [2066]
- Define magnetic susceptibility and relative permeability and establish a relation between them. [2070 ‘C’]
- Obtain the expression for the emf induced in the conductor moving in a magnetic field. [2052]
- State and explain Faraday’s law of electromagnetic induction. [2067]
- An alternating e.m.f is applied across a capacitor. Show that the current in it leads to the applied e.m.f. by 90°.
Unit Three: Modern Physics
- Describe with necessary, theory, Millikan’s oil drop experiment to determine the value of the charge associated with an electron. [2052, 2068, 2069]
- Describe an experiment to determine the specific charge of electron. [2054]
- Explain the phenomenon of discharge of electricity through gases at low pressure. [2056]
- Show that electron motion in magnetic field is circular. Prove that frequency and time period are independent with the velocity of electron. [2063]
- How are P-type and N-Type semiconductors formed? Discuss the forward biasing of a P-N junction diode. [2060]
- What is p-n-p transistor? Describe briefly a circuit of p-n-p transistor amplifier in its common emitted configuration. [2062]
- What is Zender breakdown? Describe how a Zender diode can be used as a voltage regulator? [2070 ‘C’]
- What are X-rays? Confirm with experiment the wave nature of X-rays. [2055]
- What are Bohr’s postulates? Derive the formula for the radius of the third Bohr’s orbit. [2059]
- What are the postulates of Bohr atomic model? Obtain an expression for the energy of nth orbit of hydrogen atom. [2064]
- State and explain Einstein’s mass energy relation with example. [2052]
- Discuss fission and fusion with an example of each. In which reaction is the energy released greater? [2070 ‘C’]
- Explain the term “artificial radio-isotopes”. [2054, 2054]
- Discuss energy crisis in a modern society. [2062]