Assignment 2 Nd Year PDF

## Alternating Current (DK530) ### 1. Define Alternating Current. Write down its mathematical form. Also draw its waveform. ### 2. Find the average value of AC over a complete cycle, and half cycle value. ### 3. An alternating current is given as: * I = I_osinωt + I_ocosωt Fi...

## Alternating Current (DK530) ### 1. Define Alternating Current. Write down its mathematical form. Also draw its waveform. ### 2. Find the average value of AC over a complete cycle, and half cycle value. ### 3. An alternating current is given as: * I = I_osinωt + I_ocosωt Find its average value, and rms value. ### 4. Define rms value of AC? Derive the expression for rms value of alternating current. ### 5. An AC alternating current is given as I = I_osinωt, Find its rms value over half cycle. ### 6. An alternating voltage is given as V = 220sin100πt volt. Calculate: * Peak voltage * Virtual voltage * Frequency of source voltage * Write the equation of alternating current, if the source is connected to resistor R = 2Ω. ### 7. An AC supply is mentioned as 220V, 50Hz. Write down the equation of alternating voltage. ### 8. Define inductive reactance. How is it related with self-induction and frequency. Draw the graph between capacitive reactance vs. frequency of capacitive reactance. ### 9. Define capacitive reactance. Draw the graph between capacitive reactance vs. frequency of capacitive reactance. ### 10. A capacitor blocks DC, explain? ### 11. Derive the expression for current in a purely resistive circuit when applied voltage or emf is V_osinωt. Draw the corresponding phasor diagram, and waveform diagram. ### 12. Define phasor diagram. Draw phasor diagram for R, L, & C circuit containing only: * resistor * inductor * capacitor * Series LCR circuit ### 13. An AC source V_osinωt is applied to an inductor having inductance L. Derive expression for current in the circuit. Also draw current vs. time and applied voltage vs. time graph. ### 14. A capacitor having capacitance C is connected to an AC source E=Cosωt. Derive the expression for current in the circuit. Draw wave and phasor diagram. ### 15. Derive expression for instantaneous power of an AC circuit. Also calculate average power of an AC circuit. ### 16. What is power factor? Write the value of power factor for purely resistive, inductive and capacitive circuit. ### 17. Why an ideal inductor dissipates or consumes no power? ### 18. Derive average power for purely resistive, Inductive and capacitive circuit. ### 19. Show that in case of a capacitive circuit, the frequency of instantaneous power is twice of applied voltage. ### 20. Show that power instantaneous for a resistive circuit is pulsating nature with peak amplitude. ### 21. Show that instantaneous power for purely inductive and capacitive circuit is sinusoidal nature with amplitude ±Vo. ### 22. Define wattless current. Give an example of wattless circuit. ### 23. Draw impedence triangle for a series LCR circuit, write down its impedence. ### 24. What is resonance of a series LCR circuit? Write down the condition for resonance of a LCR circuit. ### 25. Derive the expression for resonance frequency. Also draw the net impedence-frequency diagram ### 26. Draw the graph of X_L vs. f and X_C vs. f. ### 27. What is the power factor of series LCR circuit at resonance. Also calculate the power of the circuit. ### 28. Write two important features of series LCR circuit at resonance. ### 29. What is a transformer? Write down its principle. ### 30. Define transformer ratio. Also differentiate step-up or step-down transformer with one word. ### 31. Why a transformer can’t work with DC. ### 32. Why AC is more dangerous than DC? ### 33. What is AC generator? Write its principle. ## Electric field and charge and potential ### 1. The electrostatic force of repulsion between two charged ions carrying equal charges is 2 x 10⁹ N when they are separated by a distance of 5 cm. How many electrons are missing from each ion? ### 2. Define quantization of charge. ### 3. A particle of mass m, carrying charge +q, is moving around a charge of +q, in a circular path of radius r. Prove that the period of revolution of charge +q about +Q is $$T = 2\pi \sqrt \frac{mr^3}{kqQ},$$ where k is Coulomb's constant. ### 4. What is superposition principle of charges? ### 5. What is electric field? Write its unit and dimension. ### 6. Define Gauss theorem. ### 7. Write the properties of electric field lines. ### 8. What is electric flux? How is it connected with area vector? ### 9. Derive coulomb's law from Gauss law? Why do electric field lines never interest with each other. ### 10. What is electric potential? Write its unit. ### 11. Formulate the relation for the electric potential due to a point charge. ### 12. Electric potential due to a dipole at its axial/tangent positions. ### 13. Electric potential due to a system of charges. ### 14. Find out the relation between Electric field and potential. ### 15. Calculate the voltage needed to balance an oil drop carrying 10e^-when located between the plates of a capacitor which are m apart. ### 16. What are equipotential surfaces? Write its properties. ### 17. Find out the potential energy for a system of charges. ### 18. If a dipole is placed in an electric field, what is its potential energy? ### 19. What are free and bound charges? ### 20. When an electric dipole is placed in a uniform electric field making angle θ, then τ = pBsinΘ. ### 21. Find out the graph of E vs. r with distance. ## Electric field, potential and capacitance (1 mark) ### 1. What is Electric dipole and dipole moment. Define an expansion for the electric field of it's axial position. ### 2. Electric field at its end or axial position due to the dipole. ### 3. Find out the expression for the p.f. for the 2 charge system. ### 4. Show that how the forces of multiple charges affect one charge (Superposition principle) ### 5. What is Gauss theorem, Hence derive Coulomb's law from Gaurs law. Find out the E.f. due to an infinitely long charged wire. ### 6. Electric potential at its end on and outside on position. ### 7. What is capacity of a capacitor? Explain the combination of capacitors. ### 8. What is parallel plate capacitor? Find out its capacitance ### 9. Introducing a dielectric slab of thickness t. Find out the expression for the capacitance of dielectric parallel plate capacitor. ## Electric Current (2.5 marks) ### 1. Is electric current a scalar or vector quantity. Give reason. ### 2. A large number of free electrons are present in a metal, why there is no current in the absence of electric field across it? ### 3. Plot a graph showing the variation of current vs. resistance. ### 4. Why resistance becomes more in series combination? ### 5. What is a wheatstone bridge? So called? What the balancing condition of wheatstone bridge? ### 6. What do you mean by sensitivity of wheatstone bridge? ### 7. It is easier to start a car engine on a warm day than on a chilly day. Why? ### 8. If current supplied to a variable resistor is constant? Draw a graph between voltage and resistance. ### 9. What do you mean by conductivity, resistivity, and conductance of a material? ### 10. If the temperature of a conductor is increased, how it react with its resistivity? ### 11. What is series connection of cells. ### 12. What is parallel connection of cells. ### 13. What is a Wheatstone bridge? Find out the balancing condition for Wheatstone bridge. ### 14. Write down limitations of Ohm’s law. ### 15. Find out the equation for mobility of free electron. ### 16. What are bound and free electrons? ### 17. Establish a relation for current and drift velocity. ### 18. What is current density? ### 19. Write down Ohm's law? ### 20. Difference between emf and potential difference. ### 21. What is electromotive force? ### 22. Define the conventional direction of current. ## Refraction of Light (2 marks) ### 1. State laws of refraction. ### 2. The speed of light in a medium is 2.25 x 10⁸ m/sec. Find the refractive index of the medium. ### 3. On what factors does lateral displacement depend? ### 4. Define critical angle of incidence and refractive index. ### 5. Refractive index of water with respect to air is 4/3 and that of glass with respect to air is 1.5. Find the critical angle for glass-water pair. ### 6. What is total internal reflection? ### 7. Show that an illuminating object inside water can be seen only through a circular patch. ### 8. Explain why does a piece of diamond dazzle? ### 9. Why is a right angled prism a better reflector than a plane mirror? ### 10. Arrange two right-angled prisms so as to produce (i) a real image (ii) a virtual image of an object. ### 11. Do you think a double convex lens be same as bi-convex lens? Justify your answer. ### 12. An object is kept at a distance 36 cm from a convex lens of focal length 12 cm. Find the position and nature of the image produced. ### 13. Prove that the minimum distance between object and real image in case of a convex lens is 4f. ### 14. The minimum distance between an object and its real image in a convex lens is 36 cm. If the object is kept at 96 cm in case of the lens, find the position and nature of the image. ### 15. Find an expression for apparent vertical shift when a pin is kept just below the glass slab. ### 16. Prove that tan D/2 = (n – 1) tan (i/n) where D is angle of deviation and other symbols have their usual meanings. ### 17. The focal length of a convex lens in air is 24 cm. What will be its focal length in water? Given: n_l = 1.5, n_w = 4/3. ### 18. Under what condition does a converging lens behave as a diverging lens. ### 19. Find the focal length of the following in air: * bi-convex lens, n = 1.5, radii of curvature = 15 cm. * bi-concave lens, n = 1.6, radii of curvature = 20 cm. * plano-convex lens, n = 1.5, radii of curvature = 20 cm. * double convex lens, n = 1.6, radii of curvature = 12 cm, 16 cm. * plano-concave lens, n = 1.4, radii of curvature = 16 cm. ### 20. A bi-convex lens of focal length f is cut into two plano-convex lenses. Find the focal length of each lens. ### 21. Two lenses, one concave and the other convex, have focal length f’ each. Find what would be the equivalent power & position of the system? How lens depends on radii of curvature? ### 22. Define power of lens. How does the power of lens depend on radii of curvature? ### 23. Under what condition is the minimum deviation achieved in a prism? ### 24. The angle of a prism is 60^o and its refractive index is 1.5. Find the angle of minimum deviation. ### 25. A prism has angle of prism 60^o and angle of minimum deviation 38^o. Find (i) angle of incidence (ii) angle of refraction (iii) refractive index of material of the prism. ## 3 Marks Questions ## Refraction of Light ### 1. Derive expression for lateral displacement through a glass slab. ### 2. Describe the formation of mirage in a desert. ### 3. Describe the construction and working of an optical fiber. ### 4. A point object is kept in water at a depth of 2f. Find the area the point object can be seen through? ### 5. Derive expression for linear magnification in a convex lens. ### 6. Two thin lenses in contact have effective power 9D. When separated by 20 cm apart, the effective power becomes 5D. Find the focal length of each lens. ### 7. In the given U-V graph for a convex lens, determine the focal length of the lens. [Diagram with distances on the x and y axis] ### 8. In the given U-V graph for a convex lens, find the focal length of the lens. [Diagram with distances on the x and y axis] ### 9. Plot Im vs. D curve for a prism. How does the angle of deviation depend on angle of incidence? ### 10. Prove that Real depth = Apparent depth. Hence find an expression for the vertical shift. ### 11. An object is kept at a distance x from the first focus point of a Convex lens and a real image is produced at a distance x from its second focus point. Prove that the focal length of the lens is f=x²/2x. ## 5 Marks Questions ### 1. Derive thin lens formula for a convex lens. ### 2. Derive lens maker’s formula. ### 3. Derive mu = sin(A/2)/sin(D/2) for a prism where the symbols have their usual meanings. ## 2 Marks Questions ## Optical Instruments ### 1. Find an expression for the magnification of a simple magnifier when the image is produced at (i) least distance of distinct vision (ii) infinity. ### 2. Compare the objective and eyepiece of a (i) compound microscope (ii) astronomical refracting telescope. ### 3. Prove that for a compound microscope M = maximum. ### 4. What would be the magnification of a compound microscope when the object is placed very close to the focus point of objective? ### 5. What is normal adjustment of an astronomical refracting telescope? ### 6. In normal adjustment of a telescope, the magnification is 12 and the length of the tube of telescope is 91 cm. Find the focal length of the objective and the eyepiece. ### 7. What is the basic difference in the construction of a Newtonian type and a Cassegrain type reflecting telescope? ## 3 Marks Questions ### 1. Derive an expression for the magnification in an astronomical refracting telescope when the image is produced at least distance of distinct vision. ### 2. Draw the ray diagrams for a compound microscope producing an image at least distance of distinct vision ### 3. Draw the ray diagrams for the normal adjustment of an astronomical refracting telescope. ### 4. Mention the advantages of reflecting telescope over refracting telescope: ## 5 Marks Questions ### 1. Describe the construction, working, and magnification of a compound microscope. ### 2. Describe the construction, working and magnification of an astronomical refracting telescope in normal adjustment. ## Wave Optics ### 1. State Huygen’s Principle. ### 2. Explain the following: (i) ray (ii) wavefront (iii) wavelet. ### 3. Describe the construction of a new wavefront. ### 4. Determine the followings: * Phase difference when path difference is λ/8. * Path difference when phase difference is π/5. ### 5. Two slits have amplitudes in the ratio 2:5. Compare the intensity of maxima to minima during their interference. ### 6. Two light waves have intensity in the ratio 9:4. Compare the intensity of maxima to minima ### 7. Two light waves pass through two slits, the widths of which are in ratio 25:16. Compare the intensity of maxima to minima during their interference. ### 8. What are coherent Sources? ### 9. Can two independent sources be coherent? Justify. ### 10. Amplitude of light waves during interference are equal or nearly equal. Why? ### 11. How does the fringe width change when: * The screen is moved towards slits. * The slits are taken apart from each other. * The whole arrangement is dipped inside a liquid of refractive index µ. * Red light is used instead of yellow light. * The size of slits is increased. ### 12. If the arrangement of the telescope observing interference fringes is moved through 1.2 mm, 25 fringes cross the field of view. If the distance between the slits is 6 x 10^-4m, wavelength of light is 5400 Å, find the distance between the slits and the screen. ### 13. Mention the difference between two types of diffraction. ### 14. On what factors does the width of central maxima depend? ### 15. If the lens is replaced by another lens of focal length 1.2 times the previous one and wavelength of light is made 0.8 times the original value, how does the width of central maxima change? ## 2 Marks Questions ## Interference ### 1. Write the conditions for sustained interference. ### 2. Derive expression for width of central maxima. ### 3. Describe the formations of 1st and 2nd secondary diffraction due to single slit. ### 4. Describe the formation of a new wavefront on the basis of Huygen’s principle. ## 5 Marks Questions ### 1. Using Huygen’s Principle, derive the laws of reflection. ### 2. Using Huygen’s Principle, define laws of refraction. ### 3. Describe Young's double slit experiment, write an expression for fringe width. ### 4. Describe diffraction through a single slit