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Physics Guess Papers 2021 Class 12
12th Class Menu

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ACCELERATED LEARNING PROGRAMME (ALP)

LAHORE, SAHIWAL, GUJRANWALA, FAISALABAD, MULTAN, BHAWALPUR,RAWALPINDI , DERA GHAZI KHAN, AZAD KAHSMIR , SARGODHA

                                     

12th CLASS PHYSICS  GUESS PAPERS

 

 CHAPTER NO.12       ELECTROSTATICS.

MULTIPLE CHOICE:

  1. Electric lines of forces are parallel and equally spaced, than electric field is.
  1. Weak
  2. Strong
  3. Non –uniform
  4. Uniform
  1. If a charged body is moved against the electric field, it will gain.
  1. P.E.
  2. K.E.
  3. Mechanical energy
  4. Electrical potential energy.
  1. The electric field created by positive charge is.
  1. Radially inward
  2. Zero
  3. Circular
  4. Radially outward
  1. The unit of Electric intensity other than NC-1 is.
  1. V/A
  2. V/m
  3. V/C
  4. N/V
  1. 1 Joule =
  1. 6.25 x 1018 ev
  2. 6.25 x 10-18 ev
  3. 1.6 x 1019 ev
  4. 9.1 x 10-31 ev
  1. The electron volt is the unit of.
  1. Electric current
  2. Electric energy
  3. Potential
  4. Potential difference

 

  1. When some dielectric is inserted between the plates of a capacitor, then capacitance.
  1. Decreases
  2. Increases
  3. Becomes zero
  4. Becomes infinity
  1. Product of resistance and capacitance is called.
  1. Gas constant
  2. Resistivity
  3. Boltzmann constant
  4. Time constant
  1. If time constant is RC circuit is small, than the capacitor is charged or discharged.
  1. Slowly
  2. Rapidly
  3. At constant rate
  4. Intermittently

SHORT QUESTIONS:

  • Write characteristics of electric field lines.
  • Electric lines of force never cross why?
  • Describe the force or forces on a positive point charge when placed between parallel plates. With similar and equal charges.
  • Is E necessary zero inside a charged rubber balloon if balloon is spherical?
  • Give the statement of Gauss’s law. Write down its mathematical form.
  • Do electron tends to go to region of high potential or low potential.
  • The potential is constant throughout a given region of space, is electric field zero or non –zero in this region.
  • What is difference between electrical potential energy and electrical potential energy difference?
  • Define potential gradient?
  • What is meant by EEG and ERG.
  • Suppose that you follow an electric line due to a positive point charge. Do electric field intensity and the potential increase or decrease.
  • Show that  1 Volt/metre  ∞ 1= Newton/Coulomb
  • Show that 1 eV = 1.6 x 10-19 J.
  • Define electron volt, give its mathematical form.
  • Convert 1 joule into electron –volt.
  • How can you identify that which plat of a capacitor is positively charge?

LONG QUESTIONS:

  • Define electric flux. Find electric flux through a surface enclosing charge. What is electric flux? Explain.
  • State Gauss’s law. Derive relation for electric intensity at a point near an in infinite sheet of charge.
  • Define electric potential. Derive on equation for electric potential at a point due to a point charge.
  • Define Capacitor and capacitance. Find an expression for the capacitance of a parallel plate capacitor when a dielectric material is inserted between the plates.
  • Define capacitor and capacitance. Derive the formula for energy stored in a capacitor.

NUMERICAL PROBLEM

12.7   Example No. 12.4

CHAPTER NO.13        CURRENT ELECTRICITY.

MULTIPLE CHOICE:

  1. mho m-1 is the SI unit of.
  1. Conductivity
  2. Conductance
  3. Resistance
  4. Capacitance
  1. Temperature co-efficient of resistivity is measured in.
  1. ? k
  2. ? m
  3. K-1
  4. K
  1. Kirchhoff’s second rule is based on.
  1. Energy conservation
  2. Mass conservation
  3. Charge conservation
  4. Momentum conservation
  1. Reciprocal of resistance is called..
  1. Conductance
  2. Resistor
  3. Conductivity
  4. Resistivity
  1. A wire of uniform area of cross section ‘A’ and length ‘L’ is cut into two equal parts. The resistivity of each part is.
  1. Doubled
  2. Half
  3. Remains the same
  4. Increases three times
  1. If fourth band on a carbon resistor is of silver colour then its toleranceis.
  1. +- 1%
  2. +-5%
  3. +-10%
  4. +-20%
  1. A rheostat can be used as.
  1. Potential divider
  2. Rectifier
  3. Amplifier
  4. Oscillator

SHORT QUESTIONS:

  • Why does the resistance of a conductor rise with a temperature?
  • Do bands in a wire effect its electrical resistance?
  • Is the filament resistance lower or higher in a 500 watt, 220 volt light bulb than in a 100 watt, 220 volt bulb?
  • Define temperature coefficient of resistance. Give its unit.
  • What is meant by tolerance of a resistor?
  • Describe a circuit that will give continuously varying potential.
  • What is effect on drift velocity of free electrons by increasing potential difference?
  • Why the terminal potential difference of a battery decreases when the current drawn from it is increased.
  • What is short circuit and open circuit mean to you?
  • A potential difference is applied across the ends of copper wire. What is the effect on the drift velocity of free electrons by decreasing the length and temperature of the wire?
  • Give statements of Kirchhoff 1st rule and 2nd rule.
  • What is wheat stone bridge? Write down its relation for finding unknown resistance.
  • What is wheat stone bridge?

LONG QUESTIONS:

  • What is wheat stone bridge? Describe its construction and working. How can it be used to find the unknown resistance of wire?
  • Define resistivity and explain it depends upon temperature. Also derive a relation for temperature co-efficient in terms of resistivity.
  • What is potentiometer? Give its construction and how can it be used to find unknown emf.
  • A platinum wire has resistance of 10 ? at 0 oC and 20 ? at 273 oC. Find the value of temperature coefficient of resistance of platinum.
  • The resistance of an iron core at 0 oC is 1 x 104 ? . What is the resistance at 400 oC if the temperature coefficient of resistance of iron is 5.2 x 10-3 K-1.

CHAPTER NO. 14       ELECTROMAGNETISM.

MULTIPLE CHOICE:

  1. The magnetic force is simply a.
  1. Reflecting force
  2. Deflecting force
  3. Restoring force
  4. Gravitational force
  1. Tesla can be written as.
  1. Nam-1
  2. NA-1 m-1
  3. N-1 Am-1
  4. NA-1 m
  1. Magnetic density at a pint due to the current carrying conductor be determined by.
  1. Ampere’s law
  2. Faraday’s law
  3. Newton’s law
  4. Lenz’s law
  1. The SI unit of magnetic induction is.
  1. Weber
  2. Tesla
  3. Newton
  4. Weber per meter
  1. If a charge is at rest in a magnetic field than force on charge is.
  1. Zero
  2. q (p xb)
  3. q VB Sin θ
  4. q VB Cos θ
  1. The value of e/m is smallest for.
  1. Proton
  2. Electron
  3. B- particle
  4. Positron
  1. The brightness of the input on CRO screen is controlled by.
  1. Cathode
  2. Anode
  3. Grid
  4. Plato
  1. Cathode Ray Oscilloscope works by deflecting beam of.
  1. Neutrons
  2. Electrons
  3. Protons
  4. Positrons
  1. The magnetic force on a electron, travelling at 104 m/s parallel to the field of strength 1 Weber /m2 is.
  1. 10-12 N
  2. Zero
  3. 103 N
  4. 16 x10-12 N
  1. Two parallel wires carrying currents in opposite direction.
  1. Repel each other
  2. Attract each other
  3. Neither attract nor repel each other
  4. Stick to each other

SHORT QUESTIONS:

  • Define Tesla and write its formula.
  • Describe the change in magnetic field inside a solenoid carrying a steady current I, If the length of the solenoid is double but the number of turns remains the same.
  • A plane conducting loop is located in a uniform magnetic field that directed along the x-axis for what orientation of the loop is the flux maximum? For what orientation is the flux minimum?
  • Define magnetic flux give its unit.
  • Distinguish between magnetic flux and magnetic Flux density. Write their SI units.
  • Define magnetic flux and magnetic flux density.
  • Describe change in magnetic field inside a solenoid carrying steady current I if the number of turns is double but the length remain same.
  • Stat ampere’s law. Write down its formula
  • Why does the picture on a TV Screen become distorted when a magnet is brought near the screen?   
  • If a charge particle moves in a straight line through some region of space, can you say that magnetic field in the region is zero.
  • Two charged particle are projected in to a region where there is a magnetic field perpendicular to their velocities. If the charge is deflected in opposite directions, what you can say about them.
  • How can you use a magnetic field to separate Isotopes of chemical element?
  • Suppose that a charge ‘q’ is moving in a uniform magnetic field with a velocity V. Why is there no work done by the magnetic force that acts on the charge ‘q’
  • Define Lorents force. Write its formula
  • Write any two uses of CRO.
  • What is the function of grid in cathode ray oscilloscope?
  • Name the main parts of C.R.O.
  • What is Time Base Generator?
  • Is the possible to orient a current loop in a uniform magnetic field such that the loop will not tend to rotate? Explain.
  • How can a current loop be used to determine the pressure of a magnetic field in a given region of space.
  • Discuss briefly digital multi meter.

LONG QUESTIONS:

  • State Ampere’s law and apply it to find the field due to a current carrying solenoid.
  • Define Lorentz force. Determine the e/m of an electron.
  • A power line 10 m high carries a current 200 A. Find the magnetic field of the wire at the ground.
  • What current should pass through a solenoid that is 50 cm long with 10000 turns of copper wire so that it will have a magnetic field of 0.4 T?
  • How fast must a proton move in magnetic field of 2.50 x 10-3 T such that the magnetic force is equal to its weight?

 

CHAPTER NO. 15       ELECTROMAGNETIC INDUCTION.

MULTIPLE CHOICE:

  1. If we make magnetic field stronger the value of induced current.
  1. Decrease
  2. Increase
  3. Vanishes
  4. Remains constant
  1. Lenz’s law is a consequence of the law of conversation of.
  1. Charge
  2. Current
  3. Energy
  4. Momentum
  1. Lenz’s law deals with.
  1. Magnitude of emf
  2. Direction of emf
  3. Direction of induced current
  4. Resistance
  1. The notation for Henry is.
  1. V.S-1 A
  2. N.m A-1
  3. V-1 S.A
  4. V.S.A-1
  1. One of the practical applications of mutual inductance is.
  1. Step –down transformer
  2. Operational amplifier
  3. Rectifier
  4. Choke
  1. Henry is SI unit of.
  1. Current
  2. Resistance
  3. Flux
  4. Self-induction
  1. Energy stored in the indicator is.
  1. ½ L2I
  2. ½ LI
  3. ½ LI2
  4. ½ L2I2
  1. An inductor may store energy in.
  1. Its magnetic field
  2. Its electric field
  3. Its coil
  4. A neighboring circuit.

SHORT QUESTIONS:

  • Does the induced e.m.f always act to decrease the magnetic flux through a circuit?
  • Show that and ? and ? θ/?t have a same unit.
  • Does the induced emf in a circuit depend upon the resistance of the circuit? Does the induced current depend on the resistance of the circuit?
  • Is it possible to change both the area of the loop and magnetic field passing through the loop and still have no induced emf in the loop/ Explain briefly?
  • Define induced e.m.f. and induced current.
  • How should you position a flat loop of wire in a changing magnetic field so that there is no emf induced in the loop?
  • State Faraday’s law of electromagnetic induction.
  • State the Lenz’s law.
  • On what factors, the mutual inductance of two coils depends?
  • In a certain region the earth’s magnetic field points vertically down. When plane files due north, which wing tip is positively charged?
  • Define Henry.
  • Name the factors upon which the self-inductance depends.

LONG QUESTIONS:

  • Define motional emf and derive a relation for it.
  • State and prove the Faraday’s law of electromagnetic induction.
  • Define and explain mutual induction. Also derive relation for mutual inductance.
  • A metal rod of length 25 cm is moving at a speed o 0.5 ms-1 in direction perpendicular to a 0.25 T magnetic field. Find emf produced along the rod.
  • A coil of 10 turns and 35 cm3 area is in a perpendicular magnetic field of 0.5 T. The coil is pulled out of the field in 1.0 s. Find the induced emf in the coil as it is pulled out of the field.
  • A square coil of side 16 cm has 200 turns and rotates  in a uniform magnetic field of 0.05 T. If the peak emf is 12 V, what is the angular velocity of the coil?

 

CHAPTER NO.16        ALTERNATING CURRENT.

MULTIPLE CHOICE:

  1. The most common source of alternating voltage is.
  1. Motor
  2. Transformer
  3. A.C. generator
  4. All of these
  1. The sum of positive and negative peak values is called.
  1. 0
  2. 2Ie
  3. I2 e /2
  4. I2 e
  1. During each cycle AC voltage reaches a peak value.
  1. Once
  2. Twice
  3. Thrice
  4. Four times
  1. An A.C voltmeter reads 220 V, its peak value will be.
  1. 255 V
  2. 340 V
  3. 311.12 V
  4. 300 V
  1. At high frequency the value of reactance of capacitor will be.
  1. Small
  2. Zero
  3. Large
  4. Infinite
  1. A device that allows only the flow of DC through a circuit is.
  1. Inductor
  2. Capacitor
  3. AC generator
  4. Transformer
  1. When an inductor comes close to a metallic object, its inductance is.
  1. Decreased
  2. Increased
  3. Becomes half
  4. Becomes 4 times
  1. In R-C-L series circuit, the current at resonance frequency is.
  1. Minimum
  2. Zero
  3. Maximum
  4. Infinite
  1. In a three phase AC generator the phase difference between each pair of coil is.
  1. 45o
  2. 60o
  3. 90o
  4. 120o
  1. Coke consumes extremely small.
  1. Current
  2. Charge
  3. Power
  4. Potential
  1. High frequency radio wave is called.
  1. Fluctuated wave
  2. Carrier wave
  3. Matter wave
  4. Energy wave
  1. The frequency range for F.M. is given by.
  1. 88 MHZ – 108 MHz
  2. 88 KHz – 108 KHz
  3. 540 MHz – 1600 MHz
  4. 540 KHz – 1600 KHz
  1. SI unit of reactance is.
  1. Farad
  2. Volt
  3. Ampere
  4. Ohm

SHORT QUESTIONS:

  • A sinusoidal current has rms value of 10 A. What is the maximum of peak value.
  • Differentiate between peak value and peak to peak value.
  • How many times per second will an incandescent lamp reach maximum brilliance when connected to a 50 Hz source? Explain.
  • How does doubling the frequency affect the reactance of an inductor and a capacitor?
  • Name the device that will
  • At what frequency will be an inductor of 1.0 H have reactance of 500 Ohm?
  • Define impendence, also give its units.
  • In a RL circuit, will the current lag or lead the voltage? Illustrate your answer by vector diagram.
  • Write down two advantages or uses of three phase AC supply.
  • What is choke?
  • What is coke? Why is it used in AC circuit?
  • Write the conditions under which electromagnetic waves are produced from a source.
  • How the reception of a particular radio station is selected on your radio set.

LONG QUESTIONS:

  • What is RC series circuit? Derive an expression for impedance and phase angle of RC series circuit.
  • Draw the circuit diagram of (R-L-C) series resonance circuit. Discuss its behavior for A.C. and also write down its properties.
  • What are electromagnetic waves? Discuss principle of generation, transmission and reception of electromagnetic waves.
  • A 100 micro F capacitor is connected to an alternating voltage of 24 V and frequency 50 Hz. Calculate.
  • At what frequency will an inductor of 1.0 H have a reactance of 500 ohm?
  • Find the value of the current and inductive reactance when AC voltage of 220 volt at 50 Hz in passed through an inductor of 10 H.
  • A 10 mh, 20 Ohm coil is connected across 240 and 180/n Hz source. How much power does it displace?

CHAPTER NO.17        PHYSICS OF SOLIDS.

MULTIPLE CHOICE:

  1. Curie temperature for iron is.
  1. 0 K
  2. 750 K
  3. 1023 K
  4. 378 K
  1. Substance which break just after the elastic limit is reached are called as.
  1. Ductile substances
  2. Hard substance
  3. Brittle substances
  4. Soft substances
  1. Good conductor have conductivities of the order of.
  1. 10-3 (?m)-1
  2. 107 (?m)-1
  3. 102 (?m)-1
  4. 10-2 (?m)-1
  1. The potential barrier for silicon is.
  1. 0.3 V
  2. 0.5 V
  3. 0.7 V
  4. 0.8 V
  1. The most suitable metal for making permanent magnet is.
  1. Steel
  2. Iron
  3. Copper
  4. Aluminum

SHORT QUESTIONS:

  • Distinguish between crystalline and amorphous or glassy solids.
  • Define unit cell
  • Define crystal lattice.
  • Distinguish between crystalline, Amorphous and polymeric solids.
  • Define stress and Strain. What are their SI units?
  • Differentiate between ductile and brittle substances. Give an examples for each.
  • Define modulus of elasticity. Show that units of modulus of elasticity and stress are same.
  • What is meant by Strain energy? How can it be determined from the force extension graph?
  • Distinguish between a valence and conduction band.
  • What are super conductors? Write their uses
  • Define Dia and paramagnetic substance. Give one example of Dia and paramagnetic substance.

LONG QUESTIONS:

  • What is meant by strain energy? Derive the relation for strain energy in a deformed material from the area under force extension graph.
  • What is the energy and theory? How behaviors of electrical conductors, insulation and semi –conductors can be explained on the basis of energy band theory.
  • A 1.25 cm diameter cylinder is subjected to a load of 2500 kg. Calculate the stress on the bar in mega Pascal.
  • A 1 m long copper wire is subjected to stretching force and its length increase by 20 cm. Calculate the tensile strain and the percent elongation which the wire undergoes.
  • What stress would cause a wire to increase in length 0.01 % if the young modulus of the wire is 12 x 1010 Pa? What force would produce this stress in the diameter of the wire is 0.56 mm?

CHAPTER NO. 18       ELECTRONICS.

MULTIPLE CHOICE:

  1. The potential barrier for Ge at room temperature si.
  1. 0.3 volts
  2. 3 volts
  3. 1 volt
  4. 5 volt
  1. The potential barrier for silicon at room temperature is.
  1. 0.3 volt
  2. 0.4 volt
  3. 0.5 volt
  4. 0.7 volt
  1. A sensor of light is.
  1. Transistor
  2. LED
  3. Diode
  4. Light dependent resistor
  1. The central region of a transistor is called.
  1. Base
  2. Emitter
  3. Collector
  4. Neutral
  1. Find the gain of inverting amplifier of external resistance R1 = 10 K Ohm and R2= 100 K Ohm.
  1. -5
  2. -10
  3. -2
  4. 50
  1. The open loop gain of an operational amplifier is of the order of.
  1. 10+
  2. 103
  3. 102
  4. 10-1
  1. Automatic functioning of street light can be done by the use of.
  1. Inductor
  2. Capacitor
  3. emf
  4. Comparator
  1. Thickness of a base in a transistor is of the order of
  1. 10-3 m
  2. 10-9 m
  3. 106 m
  4. 106 mm
  1. Which component of the transistor has greater concentration of impurity?
  1. Base
  2. Emitter
  3. Collector
  4. Both emitter and collector

SHORT QUESTIONS:

  • What is net charge on a n-type or p-type substances?
  • How does the motion of an electron in an n-type substances differ from the motion of holes in a p-type substances?
  • The anode of a diode is 0.2 V positive with respect to the cathode, is it forward blased?
  • What is the effect of forward and reverse blasing of a diode on the width of depletion region?
  • Differentiate between forward and reverse blasing.
  • Explain why an ordinary Silicon diode does not emit light
  • Why charge carriers are not present in the depletion region?
  • Why is the photo –diode operated in reserve blased state?
  • What is photodiode? Write down its any two application.
  • Why the base current in transistor is very small.
  • Give any two characteristics of an operational amplifier.
  • Define open loop gain of operational amplifier. Also give its formula.

LONG QUESTIONS:

  • Define rectification. What are its types? Discuss half wave rectification.
  • What is a transistor? Describe the use of transistor as a amplifier and calculate its voltage gain
  • What is operational amplifier? Discuss the action of op am as inverting and non-inverting amplifier.
  • Draw the circuit diagram of non –inverting amplifier and label it. Evaluate the relations for its gain.
  • The current flowing into the base of a transistor is 100 micro A. Find its collector current Ic, emitter current I E and its ratio Ic/IE if the value of current gain B = 100.
  • In a certain circult, the transistor has a collector current if 10 mA and base current of 40 mA. What is the current gain of the transistor?

CHAPTER NO. 19       DAWN OF MODERN PHYSICS

MULTIPLE CHOICE:

  1. The value of Stefan’s constant is.
  1. 5.67 x 106 Wm -2 k-4
  2. 5.67 x 10-10 Wm-2 k-4
  3. 5.67 x 10-9 Wm -2 k-4
  4. 5.67  x 104 Wm-2 k-4   
  1. At higher energies more than 1.02 Mev the dominant process is.
  1. Photoelectron effect
  2. Compton effect
  3. Pair production
  4. Nuclear fission
  1. 1 kg mass will be equivalent to energy.
  1. 9 x 10 6 J
  2. 9 x 1012 J
  3. 9 x 1016 J
  4. 9 x 1019 J
  1. Wave nature of light appears in.
  1. Pair production
  2. Compton effect
  3. Photo electric effect
  4. Interference

SHORT QUESTIONS:

  • Photon A has twice the energy of photon B. What is the ratio of the momentum of A to that of B?
  • What happens to the total radiations from a black body if its absolute temperature is doubled?
  • Which photon red, green or blue carries the most energy momentum?
  • Which has the lower energy quanta, radio waves or X-rays.
  • When light shines on surfaces, is momentum transferred to metal surface.
  • If an electron and proton have the same de-Broglie wavelength which particle has greater speed? Explain.
  • Why don’t we observe a Compton Effect with visible light?
  • Will higher frequency light eject greater number of electros than low frequency light?
  • Define ionization potential and excitation potential.
  • Is it possible to create a single electron from energy?
  • Will the bright light eject more electrons from a metal surface then dimmer light of the same colour.
  • What advantages an electron microscope has over an optical microscope.

LONG QUESTIONS:

  • Explain de Broglie hypothesis, How Davisson and Germer experimentally verified the de Broglie hypothesis.
  • What is energy of photon in a beam of infrared radiation having wavelength 1240 nm?
  • What is the de-Broglie wavelength of electron whose kinetic energy is 120 eV?
  • An electron is accelerated through a potential difference of 50 V. Calculate its de-Broglie wavelength.
  • An electron in placed in a box about the size of an atom that is about 1.0 x 10-10 m. What is the velocity of the electron?

CHAPTER NO. 20       ATOMIC SPECTRA

MULTIPLE CHOCIE:

  1. The energy of electron in the 4th orbit of hydrogen atom is.
  1. -2.51 ev
  2. -3.50 ev
  3. -13.6 ev
  4. -0.85 ev
  1. In an electronic transition, an atom cannot emit.
  1. Gama rays
  2. Infrared rays
  3. UV rays
  4. X-rays
  1. The inverse phenomena to x-rays emission is.
  1. Diffraction
  2. Polarization
  3. Interference
  4. Photoelectric effect
  1. An electron in H atom is excited from ground state to n = 4 . How many spectral lines are possible in this case?
  1. 6
  2. 5
  3. 4
  4. 3

SHORT QUESTIONS:

  • What do we mean when we say that the atom is excited?
  • How can spectrum of hydrogen contain so many lines, whereas hydrogen atom contains one electron?
  • Can the electron in the ground state of hydrogen atom absorb a photon of energy 13.6 eV and greater than 13.6 eV?
  • What is meant by line spectrum? How line spectrum can be used for the identification of elements.
  • Write two postulate of Bohr’s model of H- atom
  • Write four uses of X-rays
  • Can x-ray be reflected, refracted, diffracted polarized just like any other waves? Explain
  • Is energy conserved when an atom emits a photon of light?
  • What are the advantages of lasers over ordinary light?
  • Explain why laser action could not occur without population inversion between atomic levels.

LONG QUESITONS:

  • What are postulates of Bohr’s model of the hydrogen atom? Show that radii of hydrogen atom are quantized.
  • What are inner shell transition & characteristics of a x-rays? Describe production of x-Rays.
  • Compute the shortest wavelength radiation in Ballmer. What value of n must be used?

 

CHAPTER NO. 21       NUCLEAR PHYSICS

MULTIPLE CHOICE:

  1. Half-life of radium .226 is.
  1. 3820 years
  2. 1940 years
  3. 1620 years
  4. 1680 years
  1. Cancer of the Thyroid gland is curved by.
  1. Carbon -14
  2. Sodium-24
  3. Iodine-131
  4. Cesium -137
  1. U is equal to.
  1. 880 Mev
  2. 931 Mev
  3. 931 eV
  4. 931 kev
  1. The mass of beta particle is equal to mass of.
  1. Proton
  2. Electron
  3. Neutron
  4. Boron
  1. When a nucleus emits alpha particle, its atomic mass decreases by.
  1. 3
  2. 2
  3. 4
  4. 1
  1. A pair of quark and anti-quark make a.
  1. Meson
  2. Harden
  3. Lepton
  4. Baryon
  1. Which group belongs to Hadrons?
  1. Protons and neutrons
  2. Mueons and neutrons
  3. Photons and electrons
  4. Positrons and electrons
  1. The number of types of quarks is.
  1. 3
  2. 4
  3. 5
  4. 6
  1. Absorbed Dose “D” is defined as.
  1. M/E
  2. E/C
  3. C/m
  4. E/M
  1. A Proton consists of quarks which are.
  1. 2 up, 3 down
  2. 1 up, 2 down
  3. All up
  4. All down

SHORT QUESTIONS:

  • What do you mean by critical mass and critical volume?
  • Define mass defect and binding energy
  • Why are heavy nuclei unstable?
  • A particle, which produces more ionization, is less penetrating. Why.
  • Define decay constant.
  • What fraction of radioactive sample decay after two half-life have elapsed?
  • If nucleus has a half-Life of one year, does this mean that is will be completely decayed after two years? Explain.
  • What do you understand by “background radiation”? State two sources of this radiation.
  • What information if revealed by the length and shape of track of an incident particle in Wilson Cloud Chamber?
  • What do you mean by the term critical mass?
  • Differentiate between Baryons and Mesons.
  • Name the basic forces of nature.
  • Define Hadrons and Leptons.

LONG QUESTIONS:

  • What is radioactivity? Discuss emission of a, b and gama particle from radioactive nuclei.
  • Explain principle construction and working of a nuclear reactor.
  • What is a nuclear reactor? Describe its four important parts.
  • Find the mass defect and binding energy of Tritium, if the atomic mass tritium is 3.016049 n.
  • Example No. 21.11
  • Exercise. 21.6
  • Exercise 21.8

                                                BEST OF LUCK

 

 




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