Inter (Part-II) Fedral Board 2014
Physics
Part II (Objective Type)
Time Allowed: 20 Minutes 
Max. Marks: 17

Note: Section-A is compulsory and comprises pages 1-2. All parts of this section are to be answered on the question paper itself. It should be completed in the first 25 minutes and handed over to the Centre Superintendent. Deleting/overwriting is not allowed. Do not use lead pencil.

Question #1
Circle the correct option i.e. A/B/C/D. Each part carries one mark.

• It is required to suspend a proton of charge 'q' and mass 'm' in an Electric Field. The strength of field must be

A.        E =  
B.         E =
C          E =
D         E =

• Two current carrying conductors are placed parallel to each other then

           
A.        They attract each other for the same direction of currents
B.         They attract each other for the opposite direction of currents
C.         They repel each other for the same direction of currents
D.        No force is present between them

• In the given circuit when switch 'S' is closed, the current through all the branches are

A.        
B.        
C.        
D.       

• The energy stored per unit volume in the electric field between the plates of charged capacitor with dielectric 

A.        U =  E2       
B.         U =  E2       
C.         U =  Ԑ0 Ԑr E2
D.        U =  

• A coil has an inductance 5.0 H. If current through it changes at the rate of 5AS-1, the emf, induced. in the coil will be

A.        2.5 V   
B.         25 V .
C.         1.0 V   
D.         V

• The energy equivalent of 1 'u mass is    

A.        931J    
B.         9.31J
C.         931 MeV         
D.        9.31 MeV

• A charge 'q' is placed stationary in a region where both the electric and magnetic fields are present. The charge will experience

A.        Both electric and magnetic forces
B.         Electric force
C.         Magnetic force
D.        No force at all

• The mathematical relation for NOR operation is

A.        X =           
B.         X =        
C.         X = B           
D.        X = A          

• The voltage gain of an inverting OP-Amplifier is

A.        G = 1 -
B.         G =
C.         G = 1 +
D.        None of these

• The Compton shift “ ∆ λ ” is equal to the Compton wavelength, if the scattered X-ray is observed at an angle ' '  for

A.         = 90°
B.          = 180°
C.          = 45°
D.        None of these

• If number of atoms in metastable state (E2) is “ N2 " and in ground state (E1) is "N1 " the population inversion means .

A.        N2 = N1
B.         N2 < N
C.         N2 > N1
D.         =

• Which phenomenon prove the particle nature of electromagnetic waves?

A.        Diffraction
B.        Polarization
C.        Interference
D.        Photoelectric effect 

• The emission of a -particle from 226 88 Ra results into new element A z Y in a reaction   where  stands for   

A.             
B.        
C.             
D.       

• The total applied voltage in the given circuit is  

A.        
B.        
C.        
D.       

• Which phase diagram is true for RC-series circuit?

A.     
B.     
C.     
D.     

• The process of combining the low frequency signal with high frequency carrier waves is called

A.        Wave transmission
B.         Modulation
C.         Resonance.
D.        Beats

• Photon 'A' has twice the energy to that of photon 'B' The ratio of momentum of 'A' to that of 'B' is

  A.         = 1
  B.          =
  C.          = 2
  D.         = 4

Inter (Part-II) Fedral Board 2014
Physics
Part II (Subjective)
Time Allowed: 3.10 Hours 
Max. Marks: 83

SECTION- B (Marks 42)

Answer any FOURTEEN parts. The answer to each part should not exceed 3 to 4 lines. (14 x 3 = 42)

• Does there exist any electric field inside a hollow charged shell? Prove your answer. How can a metal body act as electrostatic shielding for electronic devices?
• What is the maximum power output theorem? Derive its formula.
• A wire having total resistance of 32 Ω is cut into 4-equal lengths. Three of them are connected in parallel and one in series to them. Find total resistance of the combination.
• What is one electron volt energy? Derive its formula.
• There exists a magnetic field of 0.30 T in space along +X-axis. What be the magnetic force on a proton of q = 1.6 x 10-19C when it is moving with velocity 3 x 104ms-1 at an angle of 30° to the field.
• What is current sensitivity of a suspended moving coil galvanometer? How does it depend upon different factors? Describe by mathematical formula.
• When the primary of transformer is connected to a.c mains, the current in it:
  • Is very low if the secondary circuit is open, but
  • Increases when the. Secondary circuit is closed. Explain these facts.
• In a certain region, the earth's magnetic field points vertically down   = -B2 Kˆ When a plane flies due north with velocity = y jˆ which wing of the plane is positively charged and why?
• What is Reactance? Prove that the capacitive reactance  and inductive reactance  have the same units equal to that of resistance 'R' i.e. ohm.
• How is depletion region formed in PN-junction diode? What is the effect on the width of depletion region when:
  • Diode is forward biased
  • Diode is reverse biased
• What will be the ' impedance of the Rc -series circuit when frequency of applied voltage is . a. f = 0 Hz.       b.          = co Hz
• An electron and a proton moving with velocities V1 and V2 respectively have equal de.Broglies wavelengths. Find the ratio of their velocities. Which will be moving faster?
• How does an operational amplifier work as a comparator? Draw its Circuit diagram and write down its two working conditions.
• An electron is to be confined in a box of the size of nucleus (1.0 x 10-14 m). What would be the speed of the electron if it were so confined?
• If the speed of light were infinite, what would the equations of special theory of relativity reduce to?
• Differentiate between Spontaneous emission and Stimulated emission with the help of energy level diagram.
• Write the names and define three distinct ways of interaction of radiation with matter. Also give their energy range.
• Draw the circuit diagram of Wheatstone bridge and derive its balanced condition to find the un-known resistance Rx.
• If mass of proton mp = 1.6726 x 10-27 kg and mass of neutron mn = 1.6749 x 10-27kg the experimental. mass of dedutron mD = 3.3435 x 10-27kg, find the Binding energy of deuteron nucleus.

SECTION-C (Marks 26)

Note: Attempt any TWO questions.                                                                            (2 x13 = 26)
Question #3     
a. What are the main parts of AC. generator? Describe 'its principle and working. Also derive the equation of, emf induced in its coils. (07)
b. It is desired to make an a.c. generator that can produce emf of maximum value 5.0 kV with 50 Hz frequency. A coil: of area 1m2 and having 200 turns is used as armature. What should be the magnitude of magnetic field in which the coil rotates? (04)
c. Why is the core of transformer laminated?   (02)

Question #4     
a. What is Electric Potential? Derive an expression of electric potential at a point due to a point charge.    (06)
b. Using zero' reference at infinity, determine the amount by which a point 'charge of 4.0x 10-8C alters the electric potential at a point 12m away when (05)

• (a) Chargé is positive
• (b) Charge is negative.

c. Write two similarities and two differences between Electric and Gravitational forces.   (02)

Question #5     
a. Applying Bohr's Theory of Hydrogen Atom derive:                                                    (08)

• Formula of Quantized Radii
• Formula of Quantized Energies

b. An electron jumps from a level Et = -3. 5 x 10-19J to Ef = -1.20 X10-18J . What is the wavelength of the emitted light? (05)