SARGODHA BOARD 2014
PAPER PHYSICS
PART-2
Time: 20 MM
(Group-1)
Marks: 17
(Objective Part)
Note: There are THREE sections in the paper i.e. Section A, B and C.
Attempt Section -A on the same paper and return it to the Superintendent within the given time.
No marks will be awarded for Cutting, Erasing or Overwriting. Marks of Identification will lead to UFM Case Mobile Phone etc. are not allowed in the examination hall.

Q-1 Write the correct option i.e. A, B, C or Din the empty box provided opposite to each part

• The force on Neutron due to a field of 102 N I c is:

(a) 1.6x10-17N         
(b) 1.6 x 10-19 N
(c) Zero         
(d) 1.6 x10-21 N

• A Capacitor of 50 , F capacitance has P.D of 8 volt across its plates then charge on each plate of capacitor is:

(a) 4x10-4C
(b) 4x10-°C
(c) 400 C       
(d) 4 x 104C

• Color codes are used to calculate the:

(a) Nature of resistor        
(b) Numerical value of resistance
(c) Potential difference    
(d) Current

• The sensitivity of galvanometer directly depends upon:

(a) Magnetic field  
(b) Area of coil
(c) Both a,b 
(d) None of a,b,c

• The unit for permeability of free space is:

(a) -1m-1
(b) Wb A.m 
(c) WbA-2m2
(d) -1 -1

• Mutual induction play role in:

(a) Generator
(b) D.C motor
(c) Galvanometer
(d) Transformer

• A.C. generator based upon the

(a) Lenz's law          
(b) Maxwell's relation
(c) Faraday's law of electromagnet induction
(d) Mutual induction

• The A.M. transmission frequencies range from

(a) 540 kHz to 1000 kHz  
(b) 540 kHz to 1600 kHz
(c) 520 kHz to 1600 kHz  
(d) 520 kHz to 1400 kHz

• Relation far resonance frequency is:

(a)
(b)
(c)
(d)

• Which one of the following is polymeric solid:

(a) Glass       
(b) Nylon      
(c) Copper   
(d) Zinc

• Open loop gain of an operational amplifier is of the order of:

(a) 105           
(b) 106          
(c) 102           
(d) 104

• Mathematical notation for AND operation is

(a) X = A- B
(b) X = A+B  
(c) X =  
(d) X=

• The rest mass energy of an electron is:

(a) 1.02 MeV
(b) 0.51 MeV          
(c) 1.6 x 10-19J
(d) 1.51 MeV

• The unit of RH(Rydberg's constant) is:

(a) -1        
(b) m 
(c) 2
(d) -1

• The shortest wave length in Bracket Series has wave lenght:
  (a)  
  (b)
  (c) 16H       
  (d) 4RH
• Materials can be identified by measuring their:
  (a) Mass       
  (b) Half-life  
  (c) Both a, b
  (d) None of a,b,c
• Cobalt-60 is the source for:
  (a) - rays
  (b) - rays    
  (c) - rays
  (d) Neutrons

SARGODHA BOARD 2014
PAPER PHYSICS
PART-2
Time: 3:10 Hours
(Group-1)
Marks: 83
(Subjective Part)
SECTION-B
Note: Time allowed for Section -B and Section -C is 2 Hours and 40 minutes.

Q.2. Answer any Eight parts from the followings:

• How can you identify that which plate of a capacitor is positively   charged?
• What is a photoconductor?
• Electric lines of force never cross. Why?
• I necessarily zero inside a charged rubber balloon if balloon is         spherical and assume charge is uniformly distributed over the surface.
•     How can you use a magnetic field to separate isotopes of an element?
• Why the resistance of an ammeter should be very low?
• Does a uniform magnetic field affect the K.E. of a charged particle? Explain.
• Why does the picture on a TV screen became distorted when a magnet is brought near the screen?
• Does the induced emf in a circuit depend on the resistance of
  the circuit
• Show that  and  have the same unit
• Can a D.C. motor be turned in to a D.0 generator? What changes are required to be done?
• Why should an electric motor not be over loaded?

3. Attempt any EIGHT short questions. 

• Is the filament resistance lower or higher in a 500 W, 220 V light bulb than in a 100 W, 220 V bulb.
• With the help of diagram. describe a circuit that gives continuously varying potential.
• Explain why the terminal potential difference of a battery decreases when the current drawn from it is increased.
• 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 illustrate your answer by vector diagram.
• A sinusoidal current has rms (effective) value of 10A. What is the maximum peak value?
• Differentiate between intrinsic and extrinsic semi conductor.
• Write a note on super conductors.
• What is meant by para magnetic and dia magnetic substances? Give example for each.
• The anode of a diode is 0.2 V positive with respect to its cathode. Is it forward biased?
• Why ordinary silicon diodes do not emit light.
• Name the applications of photo diode.

4. Attempt any SIX short questions

• Write the two statements of uncertainty principle.
• As a solid is heated and begains to glow, why does it first appear red?
• Which photon Blue or red has greater energy and greater momentum?
• Give two advantages of Laser over ordinary Light.
• State any two postulates of Bohr's model of hydrogen atom.
• What do you mean by critical mass and critical volume?
• Define decay constant and write its unit.
• By using = mc2 show that 1.66x 10-27 kg 931 MeV
• If you swallow an - source and - source which will be more dangerous to you?

SECTION-II  
Attempt any THREE questions.

5(a) Define resistance and resistivity also explain its
dependence upon temperature.
(b) Determine the electric field at the position  =(+3) m caused by a point charge q =  = 5.0x 10-6C placed at origin.
6. (a) Derive the relation of force on a moving charge in a constant magnetic field.
(b) An ideal step down transformer is connected to main supply of 240 V. It is desired to operate a 12V, 30 W lamp. Find the current in the primary and the transformation ratio.
7. (a) Define strain? Find out strain energy in deformed materials.
(b) What is the resonant frequency of a circuit which
includes a coil of inductance 2.5 H and a capacitance 4011F
8. (a) How the transistor can be used as an amplifier? Explain in detail and calculate its gain.
(b) What is the mass of a 70 kg man in a space rocket travelling at 0.8c away from us as measured from earth.
9. (a) Describe the principle, construction and uses of G.M counter for detercting nuclear radiation.
(b) Compute the shortest wave length of radiation in "Balmer Series".

SECTION-IV 
Attempt any Four questions.   

10.(a)(i) Why a galvanometer is shunted?

• On what factors the resistance of a conductor depend?
• What is meant by internal resistance of a cell?
• Does tungsten filament obey Ohm's law or not? Explain.
• Define unit of capacitance.
• What are advantages of a transistor.
• What is meant by photo electrons?
• What does striking voltage mean?
• Write down the procedure of the experiment to find out the unknown resistance of a wire by slide wire bridge.        

     OR

Write down the brief procedure to determine the relation between current and capacitance when different capacitors are used in A.0 circuit.

1. Graph A

What do you infer from graph?
Find slope of the graph. What does it represent? 

OR
Graph B

1. What do you infer from graph?
2. Find out slope of the graph and its units from the given graph. Y-axis 90

Y-axis

90
75
60
45
30
15

0
0           2            4           6            8            10        12
          P.D(Volt)