Inter (Part-II)
Lahore Board 2013
Physics (New Scheme)
Paper: I(Group-I)
Time Allowed: 20 Minutes
Max.Marks:17
OBJECTIVE
Note: Four possible answers A,B,C and D to each question are given. The choice which you think is correct, fill that circle in front of that question with Marker or Pen ink. Cutting or filling two or more circles will result in zero mark in that question.

• The hieghest value reached by voltage or current in one cycle is called:
  

(A) Peak to peak value                                          
(B) Peak value
(C) Instantaneous value                                       
(D) Root mean square value

• The radius of autom is of the order of:
  

(A) 1010 m                                                                 
(B) 10-10 m
(C) 10-14 m                                                                
(D) 1014 m

• Conversin of A.C. into D.C. is called:
  

(A) Modulation                                                       
(B) Amplification
(C) Oscillation                                                         
(D) Rectificarion    

• The electric field created by positive charge is:

(A) Radially outward                                             
(B) Radially inward
(C) Circular                                                               
(D) Zero

• The direction of induced current is always so as to oppose the change which causes the current is:
  

(A) Faraday’s law                                                   
(B) Lenz’s law
(C) Ohm’s law                                                         
(D) Kirchoff’s 1st rule

• The radio of applied stress to volumetric strain is called:

(A) Young’s modulus                                             
(B) Shear modulus
(C) Bulk modulus                                                    
(D) Tensile modulus

• Tolerance for silver band is:
  

(A) ±10%                                                                  
(B) ±15%
(C) ±20%                                                                   
(D) ±25%

• The number of protons in an atom are always equal to number of:
  

(A) Electrons                                                           
(B) Neutrons
(C) Positron                                                              
(D) Mesons

• Which of the following series lies in the ultraviolet region?
  

(A) Lyman series                                                     
(B) Balmer Series
(C) P Fund Series                                                
(D) Mesons

• The torque on Cement Carrying Coil is:
  

(A) ԏ=NIAB cos α                                                    
(B) ԏ=BILL sin α
(C) ԏ=NIAB sin α                                                    
(D) ԏ=BILL cos α

• In 1905, the special theory of relatively was proposed by:
  

(A) Maxwell                                                            
(B) de-Brogile
(C) Bohr                                                                    
(D) Einstein

• The anode in the CRO is:

(A) Control no. of waves                                                              
(B) Control brightness of spot formed
(C) Acceleration and focus the beam                                                   
(D) At negative potential with respect to cathode

• A potential barriers of 0.7 volt exist across p-n junction made from:

(A) Silicon                                                                
(B) Germanium
(C) Indium                                                                
(D) Gallium

• Presence of dielectric always:

(A) Increase the electrostatic force                                                                   
(B) Reduces the electrostatic force
(C) Does not affect the electrostatic force                                                                  
(D) Doubles the electrostatic force

• In pure resistance A.C. circuit, instantaneous value of voltage or current:
  

(A) Current lags behind voltage                                                            
(B) Current leads voltage by π/2
(C) Both are in phase                                                                     
(D) Voltage leads current by π/2

• Which one of the following requires a material medium for their propagation?
  

(A) Heat waves                                                       
(B) X-rays
(C) Sound waves                                                    
(D) Ultraviolet rays

• Electric current produces magnetic field was suggested by:
  

(A) Faraday                                                              
(B) Oersted
(C) Henry                                                                  
(D) Lenz

Inter (Part-II)
Lahore Board 2013
Physics
Paper: II(Group-I)
Time : 2.40 Hours
Marks:68
SUBJECTIVE
(Section-I)

2. Write short answers to any EIGHT (8) questions: 16

• How can you identify that which plate of capacitor is positively charged?
• Do electrons tend to go to region of high potential or of low potential? Explain.
• Is electron volt unit of potential difference or energy? Explain.
• On which factors, does electric flux depend upon.
• How can you use a magnetic field to separate isotopes of chemical element?
• Why the resistance of an ammeter should be very low?
• What is shunt resistance? Explain briefly.
• Define magnetic flux and magnetic flux density.
• Show that ϵ and ∆ᶲ/∆t have the same units.
• Does induced emf always act to decrease the magnetic flux through a circuit?
• What is back emf in motor?
• Does the voltage output of a generator change if its speed of rotation is increased? Explain briefly.

3. Write short answers to any EIGHT (8) questions: 16

• State and briefly explain Kirchoff’s first rule (current law).
• How is a rheostat used as potential divider?
• Is the filament resistance lower or higher in a 500 W, 220 V light bulb than in 100 W, 220 V bulb?
• Name device that will:
• Permit flow of alternating current and opposes flow of alternating
• Permit flow of alternating current but not the direct current.
• What is meant by A.M. and F.M.?
• What is choke? What is its main use?
• Define stress and differentiate between volume stress and shear stress.
• Draw figure showing electrical conduction by holes in semi-conductor.
• Distinguish between crystalline and polymeric solids.
• How does motion of an electron in n-type substance differ from motion of hole in p-type substance?
• Draw symbol of XOR Gate and write its truth table.
• What are biasing requirement of a transistor for normal operation? Draw a common either amplifier circuit fulfilling these requirements.

4.  Write short answers to any SIX (6) questions: 12

• Which photon blue or red has greater energy and greater momentum?
• Photon A has twice the energy of photon B. What is the ratio of momentum of A to that of B?
• Give two postulates of special theory of relativity.
• Give two advantages of laser over ordinary light.
• Write any two postulates of Bohr’s theory.
• What factor make a fusion reaction difficult to achieve?
• Half life of Sr is 9.70 hours. Find its decay constant.
• Write down the half life of radium 226 and radon gas.
• If you swallow an α-source and β-source which would be more dangerous to you?

(Section-II)

Attempt any THREE questions.

5.a) Find charge on electron by Millikan’s method. (5)
b) A rectangular bar of iron is 2.0 cm by 2.0 cm in cross-section and 40 cm long. Calculate its resistance if resistivity of iron is 11 x 10-3 Ω-m. (3)

6.a) Define galvanometer. How it can be converted into ammeter and voltmeter? Describe them. (5)
b) An ideal step down transformer is connected to main supply of 240 V. It is designed to operate a 12V, 30 W lamp. Find the current in the primary and the transformation ratio. (3)

7.a) Explain paramagnetic, diamagnetic and ferromagnetic substances. (5)
b) What is the resonant frequency of a circuit which includes a coil of inductance 2.5 H and a capacitance of 40 µ F? (3)

8.b) Explain Heisenberg Uncertainty Principle.  (5)
b) The current flowing into the base of a transistor is 100 µ A. Find the collector current IC, its emitter current IE, the value of current gain β is 100. (3)

9.a)Define  spectroscopy, derive expression for radii of quantized orbit.  1,4
b)Find the mass defect and binding energy for tritium, if atomic mass of tritium is 3.016049 U. Mass of proton =1.007276 U,Mass of Neutron = 1.008665 U. (3)

Inter (Part-II)
Lahore Board 2013
Physics (New Scheme)
Paper: I(Group-II)
Time Allowed: 20 Minutes
Max.Marks:17
OBJECTIVE
Note: Four possible answers A,B,C and D to each question are given. The choice which you think is correct, fill that circle in front of that question with Marker or Pen ink. Cutting or filling two or more circles will result in zero mark in that question.

• SI unit of electric flux  is :
  

(A)N-mc-2                                                                 
(B)N-m2C-1
(C)N-Cm-2                                                                
(D)N-C2m-2

• For the computation of electric flux, the surface area should be:
  

(A)Flat                                                                      
(B)Curved
(C)Inclined                                                               
(D)Spherical

• The graphical representation of Ohm’s law is:
  

(A)Hyperbola                                                         
(B)Ellipse
(C)Parabola                                                            
(D)Straight line

• When a small resistance is connected parallel to the galvanometer,the resulting is:
  

(A)Voltmeter                                                          
(B)Wheatstone bridge
(C)Ammeter                                                            
(D)Potentiometer

• One weber is equal to:
  (A)NA^-1                                                                     
  (B)Nm^-1 A
  (C)NmA^-1                                                                  
  (D)Nm^-1 A^-1

• Which one of the following is not present in A.C. gemerator?

(A)Armature                                                           
(B)Magnet
(C)Slip rings                                                             
(D)Commutator

• If the motor is overloaded, then the magnitude of “Back emf”:
  

(A)Increases                                                            
(B)Decreases
(C)Constant                                                            
(D)Becomes zero

• The device which allows only the continuous flow of an A.C. through a circuit is:
  

(A)Capacitor                                                          
(B)Inductor
(C)D.C motor                                                          
(D)Battery

• At high frequency, the current through a capacitor of A.C. circuit will be:
  

(A)Large                                                                   
(B)Small 
(C)Infinite                                                            
(D)Zero

• When a stress changes the shape of a body, it is called:
  

(A)Volumetric stress                                             
(B) Shear stress
(C) Tensile stress                                                    
(D) Compressional stress

• The central region of transistor is called:
  

(A)Base                                                                    
(B)Emitter
(C)Collector                                                             
(D)Neutral

• When a P-N junction is reseve biased, the depletion region is :

(A)Widened                                                            
(B)Narrowed
(C)Normal                                                               
(D)No Change

• Joule hyper second is the unit of:
  

(A)Energy                                                               
(B)Heat
(C)Plank’s constant                                               
(D)Work

• The momentum of the moving photon is:
  

(A)Zero                                                                     
(B)P=hλ
(C)P=h/λ                                                                  
(D)P= λ/h

• A position is an antiparticle of :

(A)Proton                                                                
(B)Electron
(C)Neutron                                                              
(D)Photon

• Which of the following have no charge?
  

(A)α-rays                                                                
(B)β-rays
(C)y-rays                                                                  
(D)Cathode rays

• A pair of quark and antiquark makes:
  

(A)Meson                                                                
(B)Baryon
(C)Photon                                                                
(D)Proton

Inter (Part-II)
Lahore Board 2013
Physics
Paper: II(Group-II)
Time : 2.40 Hours
Marks:68
SUBJECTIVE

(Section-I)

2. Write short answers to any EIGHT (8) questions: 16

• Electric lines of force never cross. Why?
• Do electrons tend to go region of high potential or of low potential?
• Show that ev= 1.6 x 10-19 J.
• Define absolute potential and potential gradient.
• Why does the picture on a T.V. screen become distort when a magnet is brought near the screen?
• What is dead beat galvanometer?
• What is magnetic induction? Define its unit.
• Why voltmeter should have a very high resistance?
• Does the induced emf in a circuit depend on the resistance of the circuit? Explain.
• Show that ϵ = ∆ᶲ/∆t have the same units.
• For unmarked wires emerge from a transformer. What step would you take determine the turns ratio?
• State the following laws:
  (a) Faraday’s            (b)Lenz’s law

3. Write short answers to any EIGHT (8) questions: 16

• What is electromotive force and give its units?
• Do bends in a wire affect its electrical resistance? Explain.
• Why does the resistance of conductor rise with temperature?
• What is resonance condition?
• How many times per second will an incandesent lamp reach maximum brilliance when connected to 50 Hz source?
• How does doubling the frequency effect the reacyion of:
  (a) An indutor                     
  (b) a capacitor
• What are super condutors?
• What is meant by straine energy?
• Define stress and strain. What are their SI units?
• Write two application of photo diode.
• Why charge carries are not present in depletion region?
• Why is the base current in a transistor very small?

4. Write short answers to any SIX (6) questions: 12

• What do you understand by background radiation?
• What factors make a fusion reaction difficult to achieve?
• What do we mean by the term critical mass?
• Define decay constant and write its unit.
• Write the two statements of uncertainty principle.
• Is energy conserved when atom emits a photon of light?
•  What do we mean when we say that the atom is excited?
•  As a solid is heated and begins to glw, why does it first appear red?
• I s it possible to create a single electron from energy? Explain.

(Section-II)

Note: Attempt any THREE questions.

5.a) Write a note on electric potential at a point due to point charge. (5)
b) A charge of 90 C passes throgh a wire in one hour and 15 minutes. What is the current in the wire? (3)

6.a) Find energy stored in the inductor. (5)
b) What current should pass through a soleniod that is 0.5 m long with 10000 turns of copper wire so that it will have a magnetic field of 0.4 T?   (3)

7.a) Derive the expression for impedance and phase angle for R-C and R-L
Series circuit when excited by a.c supply. (5)
b) A 1.25 cm diameter cylinder is subjected to a load of 2500 kg. Calculate the the stress on the bar in mega Pascal. (3)

8.a) What is semiconductor iode? Explain its characteristics during forward and Reverse biased. (5)
b) An electron is accelerated through a potebtial difference of 50 volts. Calculate its de-Brogile wavelength.  (3)

9.a) Explain mass defect and binding energy. (5)
b)  Find the wavelength of the spectral line corresponding to the transition in hydrogen from n=6 to n=3 state. (3)