Sr. Inter Physics Important Questions for 2017 Very Short Answer Type Questions (2 marks) 2. RAY OPTICS AND OPTICAL INSTRUMENTS 1. Define focal length and radius of curvature of a concave lens? 2. What do you understand by the terms ‘focus’ and ‘principal focus’ in the context of lenses? 3. What is Optical Density and how is it different from mass density? 4. What are the laws of reflection through curved mirrors? 5.∗Define ‘power’ of a convex lens. What is its unit? 6.∗What ‘dispersion’? Which colour gets relatively more dispersed? 7.∗What is myopia? How can it be corrected? 8.∗What is Hypermetropia? How can it be corrected? 4. ELECTRIC CHARGES AND FIELDS 9. What is meant by the statement that ‘charge is quantized’? 10. Repulsion is the sure test of electrification than attraction. Why? 11. How many electrons constitute 1C of charge? 12. What happens to the weight of a body when it is charged positively? 13. What happens to the force between two charges if the distance between them is, a) Halved b) Doubled? 14. The electric lines of force do not intersect. Why? 15. State Gauss's law in electrostatics? 7. MOVING CHARGES AND MAGNETISM 16. What is the importance of Oersted’s experiment? 17. A circular coil of radius ‘r’ having N turns carries a current ‘i’. What is its magnetic moment? 18. What is the force on a conductor of length ‘l’ carrying a current ‘i’ placed in a magnetic field of induction ‘B’? When does it become maximum? 19.∗Distinguish between ammeter and voltmeter? 20.∗What is the principle of moving coil galvanometer? 21. What is the smallest value of current that can be measured with a moving coil galvanometer? 22.∗How do you convert a moving coil galvanometer into an ammeter? 23.∗How do you convert a moving coil galvanometer into a voltmeter? 8.∗ ∗MAGNETISM AND MATTER 24.∗What happens to the compass needles at the Earth’s poles? 25.∗What are the units of magnetic moment, magnetic induction and magnetic field? 26. Magnetic lines form continuous closed loops .Why? 27.∗Define magnetic declination? 28.∗Define magnetic inclination or angle of dip? 29.∗Classify the following materials with regard to magnetism: Manganese, Cobalt, Nickel, Bismuth, Oxygen, Copper? 30.∗Define magnetic susceptibility? Mention its unit? 9. ELECTROMAGNETIC INDUCTION 31.∗What did the experiments of Faraday and Henry show? 32.∗Define magnetic flux? 33.∗tate Faraday’s laws of electromagnetic induction? 34.∗State Lenz’s law? 35. What are eddy currents? 36.∗Define Inductance? 37.∗What do you understand by ‘self inductance’? 10. ALTERNATING CURRENT 38. What type of transformer is used in a 6V bed lamp? 39.∗What is the phenomenon involved in the working of a transformer? 40.∗What is transformer ratio? 1

41. Write the expression for the reactance of i) an inductor and ii) a capacitor? 42.∗What is the phase difference between AC emf and current in the following Pure resistor, pure inductor and pure capacitor? 43. Define power factor. On which factors does power factor depend? 44. What is meant by wattless component of current? 45. When does a LCR circuit have minimum impedance? 11.∗ ∗ELECTROMAGNETIC WAVES 46. What is the average wavelength of X-rays? 47.∗Give any two uses of infrared rays? 48. If the wavelength of electromagnetic radiation is doubled. What happens to the energy of photon? 49.∗What are applications of microwaves? 50.∗Microwaves are used in radars. Why? 51.∗How microwaves are produced? 12.∗ ∗DUAL NATURE OF RADIATION AND MATTER 52.∗What are “Cathode Rays”? 52.∗What is “Work Function”? 53.∗What is Photo Electric Effect? 54.∗Give examples of “Photosensitive Substances”. Why are they called so? 55.∗Write down Einstein’s Photo Electric Equation? 56.∗Write down the de-Broglie’s relation and explain the terms therein? 57.∗State Heisenberg's Uncertainty Principle? 15.SEMICONDUCTOR ELECTRONICS MATERIALS, DEVICES AND SIMPLE CIRCUITS 58.∗What is an n-type semiconductor? What are the majority and minority charge carriers in it? 59. What are intrinsic and extrinsic semiconductors? 60.∗What is a p-type semiconductor? What are the majority and minority charge carriers in it? 61.∗What is a p – n junction diode? Define depletion layer? 62.∗How is battery connected to junction diode in 1) Forward Bias 2) Reverse Bias 63. What is zener voltage(Vz) and how will a zener diode be connected in circuits generally? 64.∗Draw the circuit symbols for p-n-p and n-p-n transistors? 65. Define amplifier and amplification factor? 66. In which bias can a zener diode can be used as voltage regulator? 67.∗Which gates are called universal gates? 16.∗ ∗COMMUNICATION SYSTEMS 68. What are the basic blocks of a communication system? 69. What is “World wide web” (WWW)? 70.∗Mention the frequency range of speech signals? 71.∗What is sky wave propagation? 72.∗Define modulation. Why is it necessary? 73.∗Mention the basic methods of modulation? 74.∗Which type of communication is employed in Mobile Phones?

Short Answer Type Questions (4 marks) 2. RAY OPTICS AND OPTICAL INSTRUMENTS 1. Define focal length of a concave mirror. Prove that the radius of curvature of concave mirror is double its focal length? 2.∗Define critical angle? Explain total internal reflection using a neat diagram? 3.∗Explain the formation of mirage? 4.∗Explain the formation of a Rainbow? 5.∗Why does the setting Sun appear red? 6.∗With a neat labeled diagram explain the formation of image in a simple microscope? 2

3. WAVE OPTICS 7.∗Explain Doppler Effect in light. Distinguish between Red Shift and Blue Shift? 8.∗Derive the expression for the intensity at a point where interference of light occurs. Arrive at the conditions for maximum and zero intensity? 9.∗Does the principle of conservation of energy hold for interference and diffraction phenomena? Explain briefly? 10.∗How do you determine the resolving power of your eye? 4. ELECTRIC CHARGES AND FIELDS 11.∗State and explain Coulomb’s inverse square law in electricity? 12. Define intensity of electric field at a point. Derive an expression for the intensity due to a point charge? 13.∗Derive the equation for the couple acting on an electric dipole in a uniform electric field? 14.∗Derive an expression for the electric intensity of electric field at a point on the axial line of an electric dipole? 15.∗Derive an expression for the electric intensity of electric field at a point on the equatorial line of an electric dipole? 16. State Gauss's law in electrostatics and explain its importance? 5. ELECRTO STATIC POTENTIAL CAPACITANCE 17.∗Derive an expression for the capacitance of a parallel plate capacitor? 18. Derive an expression for the electrostatic potential energy of a system of two point charges and find its relation with electric potential of a charge? 19. Explain the behavior of a dielectric in an external field? 20. Three capacitors of capacitances 1µF,2µF and 3µF are connected in parallel. a) What is the ratio of charges b) What is the ratio of potential differences? 21. Three capacitors of capacitances 1µF , 2µF and 3µF are connected in series a) What is the ratio of charges? b) What is the ratio of potential differences? 22.∗Derive the formula for equivalent capacitance when the capacitors are connected in series? 23.∗Derive the formula for equivalent capacitance when the capacitors are connected in parallel? 7.MOVING CHARGES AND MAGNETISM 24.∗State and explain Biot – Savart law? 25.∗State and explain Ampere’s law? 26. Find the magnetic induction due to a long current carrying conductor? 27.∗Derive an expression for the magnetic induction at the centre of a current carrying circular coil using BiotSavart law? 9. ELECTROMAGNETIC INDUCTION 28.∗Obtain an expression for the emf induced across a conductor which is moved in a uniform magnetic field which is perpendicular to the plane of motion? 29.∗Describe the ways in which Eddy currents are used to advantage? 30.∗Obtain an expression for the mutual inductance of two long co-axial solenoids? 13.ATOMS 31.∗What are the limitations of Bohr’s theory of hydrogen atom? 32.∗Explain the different types of spectral series of Hydrogen atom? 15. SEMICONDUCTOR ELECTRONICS MATERIALS, DEVICES AND SIMPLE CIRCUITS 33.∗Describe how a semi -conductor diode is used as a half wave rectifier? 34.∗What is rectification? Explain the working of a full wave rectifier? 35. Distinguish between the half- wave and full – wave rectifiers? 36. Explain the working of LED and what are its advantages over conventional incandescent low power lamps? 37. Define NAND and NOR gates. Give their truth tables? 38. Explain the operation of a NOT gate and give its truth table?

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Important Long Answer Type Questions (8 marks) 1. WAVES 1. ∗Explain the formation of stationary waves in an air column enclosed in open pipe? Derive the equations for the frequencies of harmonics produced? 2.∗How are stationary waves formed in a closed pipe? Explain the various modes of vibrations in a closed pipe and establish the relation between their frequencies? 3. What is Doppler Effect? Obtain expression for the apparent frequency heard when the source is in motion with respect to an observer at rest? 4. What is Doppler’s shift? Obtain an expression for the apparent frequency of sound heard when the observer is in motion with respect to a source at rest? 5.∗Explain the formation of stationary waves in stretched strings and hence deduce the laws of transverse waves in stretched strings? 6. CURRENT ELECTRICITY 6.∗State Kirchhoff’s law for an electrical net work. Using these laws deduce the condition for balance in a Wheatstone bridge? 7.∗State the working principle of potentiometer. Explain with the help of a circuit diagram how the emf of two primary cells is compared by using the potentiometer? 8.∗State the working principle of potentiometer explain with the help of a circuit diagram how the potentiometer is used to determine the internal resistance of the given primary cell ? 14. NUCLEI 9. What is radioactivity? State the law of radioactive decay. Show that radioactive decay is exponential in nature? 10.∗Explain the principle and working of a nuclear reactor with the help of a labeled diagram?

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