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2nd Year Physics Guess

 

2ND YEAR PHYSICS  GUESS FOR EXAMINATION 2023

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SHORT QUESTIOhNS

(i)     The potential is constant throughout a given region of space. Is the electrical field zero or non-zero in this region? Explain.

(ii)   How can you identify that which plate of a capacitor is positively charged?

(iii) Describe the force on a positive point charge when placed between parallel plates;

a.       With similar and equal charges               b. with opposite and equal charges

(iv)  Electric lines of force never cross. Why?

(v)    If a point charge q of mass m is released in a non-uniform electric field with field lines pointing in the same direction, will it make a rectilinear motion?

(vi)  Do electrons tend to go to region of high potential or of low potential?

(vii)                     A potential difference is applied across the ends of a copper wire. What is the effect on the drift velocity of free electrons by;

a.       Increasing the potential difference      b. decreasing the length and the temperature of the wire

(viii)          Do bends in a wire affect its electrical resistance? Explain.

(ix)  Why does the resistance of a conductor rise with temperature?

(x)    What are the difficulties in testing whether the filament of a lighted bulb obeys Ohm’s law?

(xi)  Is the filament resistance lower or higher in a 500 W, 220V light bulb than in a 100W, 220 V bulb?

2nd Year All Subject Original Past Ppaers


(xii)                     Describe a circuit which will give a continuously varying potential.

(xiii)          A plane conducting loop is located in a uniform magnetic field that is directed along the x-axis. For what orientation of the loop is the flux a maximum? For what orientation is the flux a minimum?

(xiv)          A current in a conductor produces a magnetic field, which can be calculated using Ampere’s law. Since current is defined as the rate of flow of charge, what can you conclude about the magnetic field due to stationary charges? What about moving charges?

(xv)            Describe the change in the magnetic field inside a solenoid carrying a steady current I,  if (a) the length of the solenoid is doubled but the number of turns remains the same and (b) the number of turns is doubled, but the length remains the same.

(xvi)          At a given instant, a proton moves in the positive x direction in a region where there is magnetic field in the negative z direction. What is the direction of the magnetic force? Will the proton continue to move in the positive x direction? Explain.

(xvii)        How can a current loop be used to determine the presence of a magnetic field in a given region of space?

(xviii)      Why the resistance of an ammeter should be very low?

(xix)          Does the induced emf in a circuit depend on the resistance of the circuit? Does the induced current depend on the resistance of the circuit?

(xx)            A light metallic ring is released from above into a vertical bar magnet. Viewed for above, does the current flow clockwise or anticlockwise in the ring.

(xxi)          Does the induced emf always act to decrease the magnetic flux through a circuit?

(xxii)        How would you position a flat loop of wire  in a changing magnetic field so that there is no emf induced in the loop?

(xxiii)      In a certain region the earth’s magnetic field point vertically down. When a plane files due north, which wingtip is positively charged?

(xxiv)        Show that  have the same units. 

(xxv)         Is it possible to change both the area of the loop and  the magnetic field passing through the loop and still not have an induced emf in the loop?

(xxvi)       Can an electric motor be used to drive an electric generator with the output form the generator being used to operate the motor?

(xxvii)     A suspended magnet is oscillating freely in a horizontal plane. The oscillations are  strongly damped when a metal plate is placed under the magnet. Explain why this occurs?

(xxviii)   When the primary of a transformer is connected to A.C mains the current in it; (a) is very small if the secondary circuit is open, but (b) increases when the secondary circuit is closed. Explain these facts. 

(xxix)       Name the device that will (a) permit flow of direct current but oppose the flow of alternating current (b) permit flow of alternating current but not the direct current.

(xxx)         How many times per second will an incandescent lamp reach maximum brilliance when connected to a 50Hz source?

(xxxi)       A circuit contains an iron-cored inductor, a switch and a D.C. source arranged in series. The switch is closed and after an interval reopened. Explain why a spark jumps across the switch contacts?

(xxxii)     How does doubling the frequency affect the reactance of (a) an inductor (b) a capacitor?

(xxxiii)   In a R-L circuit, will the current lag or lead the voltage? Illustrate you answer by a vector diagram.

 

(i)                 Differentiate b/w Bulk and shear modulus.

(ii)   What do you mean by ultimate tensile stress?

(iii) How p-type and N-type substances are made from intrinsic semi-conductors.

(iv)  Differentiate b/w paramagnetic and ferromagnetic materials.

(v)    What do you mean by coercivity and coercive current.

(vi)  How does  the motion of an electron in a n-type substance differ from the motion of holes in a p-type substance?

(vii)                     Whatis the net charge on a n-type or a p-type substance?

(viii)                   The anode of a diode is 0.2V positive with respect to its cathode. Is it forward biased?

(ix)  Whatis the effect of forward and reverse biasing of a diode on the width of depletion region?

(x)    Why ordinary silicon diodes do not emit light?

(xi)  Why a photo diode is operated in reverse biased state?

(xii)            The potential is constant throughout a given region of space. Is the electrical field zero or non-zero in this region? Explain.

(xiii)          How can you identify that which plate of a capacitor is positively charged?

(xiv)          Describe the force on a positive point charge when placed between parallel plates;

a.       With similar and equal charges                 b. with opposite and equal charges

(xv)            Electric lines of force never cross. Why?

(xvi)          If a point charge q of mass m is released in a non-uniform electric field with field lines pointing in the same direction, will it make a rectilinear motion?

(xvii)        Do electrons tend to go to region of high potential or of low potential?

(xviii)      A potential difference is applied across the ends of a copper wire. What is the effect on the drift velocity of free electrons by;

a.       Increasing the potential difference        b. decreasing the length and the temperature of the wire

(xix)          Do bends in a wire affect its electrical resistance? Explain.

(xx)            Why does the resistance of a conductor rise with temperature?

(xxi)          What are the difficulties in testing whether the filament of a lighted bulb obeys Ohm’s law?

(xxii)        Is the filament resistance lower or higher in a 500 W, 220V light bulb than in a 100W, 220 V bulb?

Describe a circuit which will give a continuously varying potential.

(i)      Bohr’s theory of hydrogen atom is based upon several assumptions. Do any of these assumptions contradict classical physics?

(ii)    Can the electron in the ground state of hydrogen absorb a photon of energy 13.6eV?

(iii)   Is energy conserved when an atom emits a photon of light?

(iv)  What do we mean when we say that the atom is excited?

(v)    What are isotopes? What do they have in common and what are their differences?

(vi)  Why must a Geiger Muller tube for detecting α-particles have a very thin end window? Why does a Geiger Muller tube for detecting -rays not need a window at all?

(vii) What do we mean by the term critical mass?

(viii)        What factors make a fusion reaction difficult to achieve?

(ix)  How can radioactivity help in the treatment of cancer?

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2nd Year Physics Past Papers 

LONG QUESTION

Q. (a) Define and  explain polarization of dielectric, give a complete description of dielectric constant after establishing

        the relation for capacitance of a parallel plate capacitor.                                                                                                      (05)

        (b) in Bohr’s atomic model of hydrogen atom, the electron is in an orbit around the nuclear proton at distance of

         with a speed of  (e =  mass of electron = ). Find

         (i) The electric potential that a proton exerts at this distance  (ii) total energy of the atom in eV (iii) The ionization

         energy for the atom in eV.                                                                                                                                                                         (03)

.       Q  (a) State kickoff’s voltage rule and use it to derive the expression for wheatstone bridge.                                  (05)

(b) Find the current which flows in all the resistance of the circuit of following Fig.                                                                (03)


Q.        (a) Describe Lorentz force law and give procedure and derive relations for conversion of galvanometer into a

        Voltmeter and ammeter.                                                                                                                                                                     (05)

        (b) What current should pass through a solenoid that is 0.5 m long with 10.000 turns of copper wire so that it will

        have a magnetic field of 0.4T?                                                                                                                                                           (03)

Q.              (a) Briefly describe motional emf’s equation with emphasis on the – ive sign and use it to derive the equation of a

        transformer along with it’s principle and construction.                                                                                                         (05)

        (b) a copper ring has a radius of 4.0cm and resistance of 1.0 m Ω. A magnetic field is applied over the ring,

        perpendicular to its plane. If the magnetic field increases from 0.2T to 0.4T in a time interval of  5 x10–3s, what is the

        current in the ring during this  interval?                                                                                                                                       (03)

Q.              (a) describe in detail the behavior of a capacitor with the passage of AC through it.                                          (05)     

        (b) A 10mH, 20 Ω coil is connected across 240V and 180/Ï€ Hz source. How much  power does it dissipate?  (03)

(a)Write a detailed note on transistor as an amplifier.                                                                                                  (05)

        (b)The Length of a steel wire is 1.0 m and its cross-sectional area is . Calculate the work done in

        stretching the wire when a force of 100N is applied within the elastic region. Young’s modulus of steel is

        .                                                                                                                                                                               (03)

 

 

Q. (a)Write detailed note on photoelectric effect alongwith Einstein’s explanation.                                                    (05)

        (b)A 90 keV X-rays photon is fired at a carbon target and Compton scattering occurs. Find the wavelength of the

        incident photon and the wavelength of the scattered photon for scattering angel of (a) 30(b) 60.                        (03)

Q. (a)Find the expressions for (i) Radius & (ii) energy of a hydrogen atom.                                                                       (05)

        (b)Calculate the longest wavelength of radiation for the Paschen series.                                                                     (03)

Q. (a)Define and  explain polarization of dielectric, give a complete description of dielectric constant after establishing

        the relation forcapacitance of a parallel plate capacitor.                                                                                                       (05)

        (b)in Bohr’s atomic model of hydrogen atom, the electron is in an orbit around the nuclear proton at distance of

2nd Year Physics Past Papers 

2nd Year Physics Past Papers 

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