Lahore Board 2012 Part 2
Inter (Part I) Inter (Part-I) Lahore Board 2012
Physic (Compulsory)
  Paper II (Objective Type)
Time Allowed: 20 Minutes Max.
Marks: 17
(Group-I)

Note: Four Possible answers A, B, C and D to each question are the given. The choice which you think is correct, fill that circle in front of that question with marker or pen ink in the answer-book cutting or filling two or more circles will result in zero mark in that question. Write the letter A,B,C or D in the Colum (Write correct option) against  each question also .if there is a contradiction in the bubble and hand written answer, bubble option will be considered correct

• 1 unit of plank’s constant is :
  

(A) Volt     
(B) j.s  
(C) j.s^-1
(D) e.v

• For holography we use a bean of:
  

(A) y-rays
(B) x-rays
(C) B-rays  
(D) Laser

• The brightness of  spot on CRO screen is controlled by :
  
  (A) anodes    
  (B) cathodes 
  (C) Grid
  (D) Plates
  
  
• Be emitting B-particle and Y-particle simultaneously the nucleus changes its charge by :
  

(A) Losses by 1 
(B) Increases by 1  
(C) Increases by 2    
(D) No

• Power dissipation in a pure inductive or in a pure capacitance circuit is :

(A) Infi 
(B) Zero
(C) minimum       
(D) Maximum

• which of the following are elementary particles :
  

(A) Protons       
(B) Neutrons   
(c)  Photons  
(D) Mesons

• One Henry is equal to:

(A) Vs^-1A
(B) N.mA^-1            
(C) V^-1.S.A                 
(D) V.S.A^-1

• The force experience by until positive charge placed at a point in an electric filed is called:
  

(A) Coulomb’s force
(B)  faraday’s force  
(C) Lorentz’s force  
(d) Electric filed intensity

•  In Compton scattering the Compton shift Δƛ, will be equal to Campton wavelength, if the scattering angle is :
  

(A) Zero 
(B) 45⁰
(C) 60⁰  
(D) 90⁰

• Which of the following series of H-spectrum lies in ultraviolet region :
  

(A) Lyman series         
(B) Blamer series   
(C) Paschen  series   
(D) Bracket series

• Reciprocal of bulk modulus is :
  
  (A)  Elasticity   
  (B)  Young modulus  
  (c)  Compressibility      
  (D)  Shear modulus
  
  
• The relation for maximum value of deflecting couple is given by:
  
  (A)    =b/NIA     
  (B) Ꮨ=BINA      
  (C) Ꮨ =BNA(D)  
  (D) Ꮨ  =BNAθ
   
  
• To construct a step down transformer for :

(A) Ns< Np  
(b)  Np<Ns   
(C) Ns=Np    
(D) Ns.Np=1

•      r  =  µ₀I is the relation for :
  

(A) Millikan’s law                  
(B) Gauss’s law                 
(C) Ampere’s law             
(D)  Lenz’s law

•  For non-invering amplifier if R₁= æ ohm and R₂=o ohm, then gain of amplifier is : 
  (A) -1 
  (B) Zero 
  (C) +1    
  (D) Inifinite
  
  
• Curi temperature for. iron is :
  

(A) 0 k  
(B) 570 k    
(C) 1023 k  
(D) 378

• The word”Zerography” means :
  

(A) Writing by left hand  
(B) Writing by children    
(C) dry writing   
(D) Writing by water colours

Inter (Part-II) Lahore Board 2012
PHYSICS 
PAPER: II (Essay TYPE)
Time: 2:40 Hours   
Max. Marks: 68
(Group – I)
SECTION – I

2. Write short answers to any EIGHT (8) Questions:

• If a point charge q of mass m is released in a non uniform electric filed with filed lines pointing in the same direction, will it make a rectilinear motion?
• Do electrons tend to go to region of high potential or of low potential?
• Is E necessarily zero inside a charges rubber balloon if balloon is spherical? Assume that charge the filament of a lighted over the surface.
• What are the difficulties in testing whether the filament of a lighted bulb obeys ohm’s law?
• Is the filament resistance lower or higher in a 500 w, 220 v light bulbs than in a 100 w, 220 v bulbs?
• Describe a circuit which will give a continuously varying potential.
• Why the voltmeter should have a very high resistance?
• Why does the picture on a TV screen become distort 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 the magnetic field in the region is zero?
• Show that E and  have the same units.
•  In a certain region the earth’s magnetic field point vertically down, when a plane flies due north, which wingtip is positively charged?
• When an electric motor, such as an electric drill, is being used, does it also act as a generator? If so what is the consequence of this?

3.  Write short answers to any EIGHT (8) questions:

• What do you mean by back emf effect in a motor?
• How many times per second will an incandescent lamp reach maximum brilliance when connected to a 50 Hz source?
• In a RC circuit, will the current lag or lead the voltage? IIIustrate your answer by a vector diagram.
• What is choke coil and where is it used?
• What meant by diamagnetic and ferromagnetic substances?
• Define curie’s temperature. What is its value for iron?
• How will you obtain n-type material from pure silicon?
• What is the effect of forwarded and reveres biasing of a diode on the width of the depletion region
• Why a photodiode is operated in reverse-biasing sate?
• What is the biasing requirement of the junction of a transistor for its normal operation?
• Is it possible to create single electrons from energy? Explain
• Photon a has twice the energy of photon B.what is the ratio of the momentum of a to that of B.

4. Write short answer to any six (6) question: 12

• Differentiate between inertial and non-inertial frame of reference.
• What is meant by pair production and annihilation of matter?
• Write down the two advantages of laser over ordinary light.
• How the spectrum of hydrogen cans contains one electron?
• How does a ka X-rays differ from kβ X-rays?
• Define mass defect and binding energy.
• What do we mean by the term critical mass?
• If someone accidentally swallow an α-source and α β- source, which would be the more dangerous to him?  Explain Why?
• Differentiate between baryons and mesons.

(Section – II)

Attempt any Three question.

5. (a) What is Wheatstone bridge? Describe its construction and working.
(b)  A capacitor has a capacitance of 2.5x10^-8  F.in charging process, electrons are removed from one plate and placed on the other one. When a potential between the plates in 450 v , how mane electrons have been transferred?

6. (a) State and explain lens’s law. How this law explains conservation of energy during electromagnetic induction?
(b) Alpha particles ranging in speed from 1000 ms^-1 to 2000 300 vm^-1 and the magnetic induction is 0.20 T. which particles will move undeviated?

7. (a) What is R.C series circuit? Calculate the impedance and phase angel of R.C series circuit?
(b) The length of a steel wire is 1 m and its cross-sectional area is 0.03x10^-4 m². Calculate the work down in stretching the wire when a force of 100 N is applied within the elastic region. (Modulus of steel is 3x10^-11 Nm^-2)

8. (a) Draw the circuit diagram of non-inverting amplifier and label it. Evaluate a relation for its gain.
(b) A particle of mass 5.0 mg moves with speed of 8.0 ms^-1 Calculate its de-Broglie wavelength. (h=6.63x10^-34 J.S.)

9. (a) What  is radioactive? Discuss emission of α,β and Y particles from radioactive nucelei.
(b) Electrons in an x-ray od 3000 v. if these electrons were slowed down in a target, what will be the minimum wavelength of x-ray produced?

 
Lahore Board ( Part-II) 2012
Inter (Part I) Inter (Part-I) Lahore Bo012
Physic (Compulsory)   
Paper II (Objective Type)
Time Allowed: 20 Minutes Max.  
Marks: 17

Note: Four Possible answers A, B, C and D to each question are the given. The choice which you think is correct, fill that circle in front of that question with marker or pen ink in the answer-book cutting or filling two or more circles will result in zero mark in that question. Write the letter A,B,C or D in the Colum (Write correct option) against  each question also .if there is a contradiction in the bubble and hand written answer, bubble option will be considered correct

• The substances in which the atoms do not magnetic dipole are called:
  

(A) Ferromagnetic         
(B) Paramagnetic     
(C) Diamagnetic     
(D) Conductor

• When platinum wire is hated, then it becomes--------at temperature about 16000 C:

(A) White                          
(B) Yellow        
(C) Green          
(D) Dull red

• A wire of resistance R is cut into equal parts, its resistance becomes R/2 what happens to resistivity
  

(A)Double  
(B) Same
(C) Half  
(D)One fourth

• Production of x-rays can be regarded as the inverse of :

(A)  Compton effect  
(B) Pair production   
(C) Photo electric effect  
(D) Annihilation of matter

•   Pure choke consumes:

(A) Minimum power    
(B) Maximum power   
(C) No power  
(D) Average power

• Neutron was discovered in 1932 by :

(A) Bohr
(B) Chadwick 
(C) Dirac  
(D) Fermi

• The mutual induction between two colis depends upon :

(A)   Area of the coils  
(B) Number of the turns  
(C) Distance between the coils 
(D) All of these

• Presence of dielectric always:
  
  (A)Increases the electricity force  
  (B) Decreases the electricity of force  
  (C) Does not affect the electricity force
  (D) doubled the electricity force
  
  
• An expression for current gain of a transistor is given by :
  

(A) β=   
(B)    
(C)    
(D)

• The number of electrons emitted depends upon :

(A) Colour of target surface   
(B) Shape of the surface   
(C) Frequency of incident light  
(D) Intensity of incident light

• In modulation, law frequency signal is known as:

(A)  Loaded signal 
(B) Fluctuated signal  
(C) Harmonic signal   
(D) Modulation signal

• In liquids and gases, the current due to the motion of:

(A) Negative charges    
(B)  Positive charges
(C) Neutral particle
(D) Both negative and positive

• If we make the magnetic field stronger, the value of induced current is:

(A) Decreased   
(B) Increased 
(C) Vanished  
(D) Kept constant

• The anode in the cathode ray oscilloscope:

(A) Control number of waves    
(B) Control the brightness of spot formed  
(C) Accelerates and focus beam   
(D) At negative potential with respect to cathode

• Substances which break just after the elastic limit is reached are called:

(A) Ductile substances 
(B) Hard substances  
(C) Soft substances  
(D) Brittle substances

• Type of quarks are :

(A) 4 
(B) 6
(C) 8
(D) 10

• A capacitor is perfect for :

(A) Alternating current
(B) Direct current   
(C) Both a & B
(D) none of these

Inter (Part-II) Lahore Board 2012
PHYSICS 
PAPER: II (Essay TYPE)
Time: 2:40 Hours   
Max. Marks: 68
(Group – II )   
SECTION – I

2. Write short answers to any EIGHT (8) Questions:

• How can identify that which plate of a capacitor is positively charged?
• If a point charged ‘q’ of mass ‘m’ is released in a non-uniform electric filed with filed lines pointing in the same direction, will it make a rectilinear motion?
• When a dialectic slab is inserted between two oppositely charged parallel plates, what happens to electric filed in the region between plates?
• Compare e.m.f of a battery and potential drops across a conductor.
• How can a current loop be used to determine unknown resistance? (avoid details of Wheatstone bridge)
• Briefly discuss a circuit which will give continuously varying potential.
•  How can a current loop be used to determine the presence of a magnetic field in a given region of space?
• Why is there no work done by magnetic field on a charge ‘q’ moving in it?
• How will you convert a galvanometer it a voltmeter? Write formula for required resistance and explain terms used in it.
• What is a commutator? What is its use?
• Can an electric motor be used to drive an electric generator with the output of generator being used to operate motor?
• When the primary of a transformer is connected to a.c mains, the current in it :

• Define mutual inductance and its units.
• 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.
• What is meant by AM and FM? Describe their frequency ranges.
• A 100µF capacity is connected to an alternating voltage of 24 volt an frequency 50 Hz. Calculate the reactance of the capacitor.
• What is meant by hysteresis loss? How is it used in the construction of a transformer?
• Give the order of conductivity of:(a)conductors.(b) semi-conductor.
• Differentiate between super conductor and high temperature super conductors.
• The anode of a diode is 0.2 volt positive with respect to its cathode. Is it forward biased?
• What is the principle of virtual ground?
• Draw the circuit symbol for:( a) n p n (b) pnp transistor.
• If an electron and patron have same de Broglie wavelength, which particle has greater speed?
  When does light behave asa wave? When does it behave as a particle?

• Give two postulates of special theory of relativity.
• What is the energy of a photon in a beam of infrared radiation of wavelength 1240 nm?
• What do we mean when we say that atom is excited?
• Write two postulates of bohr’s model of H-atom.
• Explain why laser action could not occur without population inversion between  atomic levels.
• What do you mean by the “dead time” of a Geiger counter?
• What are isotopes? What do they have in common and what are their differences?
• A particle which produced more ionization is less penetrating, why?
•  How can radioactivity help in the treatment of cancer?
  

(Section-II)

Attempt any three questions.

5. (a) State gauss’s law and find electric intensity due to an infinite sheet of charge.
(b)   A rectangular bar of iron is 2 cm by 2 cm in cross section and 40 cm long. Calculate its resistance if the resistivity of iron is 11x10-8 Ὢ m.

6. (a) define motional e.m.f. and derive a relation for it.
(b) B=(40-18K) Wbm^-2. How much flux passes through a 5.0 cm² area loopo in this region if the loop lies flat in xy-plane?

7. (a) Explain conductor, insulators and semiconductor on the bases of energy band theory.
(b) What is the resonant frequency of a capacitance of 40µF?

8. (a) Explain pair production and annihilation of matter.
(b) The current flowing into the base of a transistor is 100µA. find its collector current Ic and its emitter current IE if value of current gain is 100.

9. (a) what is nuclear reactor? Describe the function of its main parts.
(b) A tungsten target is struck by electron that has been accelerated from rest through 40 KV potential differences. Find the shortest wavelength of the bremstrahlung radiation emitted.