Inter (Part-II) Dera Ghazi Khan Board 2013
Physics
Part II (Objective Type)
Time Allowed: 20 Minutes 
Max. Marks: 17

Note: You have four choices for each objective type question as A, B, C and D. The choice which you think is correct; fill that circle in front of that question number. Use marker or pen to fill the circles. Cutting or filling two or more circles will result in zero mark in that question.

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

• If the distance between two point charges is double the for

(A) Double  
(B) Half                       
(C) Three times
(D) One -fourth

• Unit of electric intensity other than NC is

(A) V/A                       
(B) m/V                       
(C) V/m                       
(D) V/C

• The SI unit of “B” is tesla which is equal to

(A)                        
(B)          
(C)  
(D)      

• The brightness of the spot of the CR0 on the screen is controlled by

(A) Cathode    
(B) Anode       
(C) Grid             
(D) Plate

• Energy stored per unit volume in the inductor is

(A) 1/2 LI2              
(B) B2 /2 uo     
(C) B2 /4 uo     
(D) 1/2 L2 I

• One Henry is equal to

(A) V S-1 A     
(B) V S A-1      
(C) V A-1 S-1       
(D) V-1 S A

• At high frequency , the value of reactance of capacitor in A.C. Circuit is

(A) Small        
(B) Large         
(C) zero           
(D) Medium

• SI unit of impedance is

(A) Henry       
(B) Hertz         
(C) Farad         
(D) Ohm

• Curie temperature for Iron is about

(A) 750 K        
(B) 750 °F        
(C) 750 °C       
(D) - 273 °C

• Potential barrier for Silicon (Si) at room temperature is 

(A) 0.3 V         
(B) 0.7V          
(C) 0.9 V         
(D) 0.5 V

• The open loop gain of the OP-amplifier is of the order of

(A) 107            
(B) 105            
(C) 103            
(D) 106

• All the motions are

(A) Absolute  
(B) Uniform    
(C) Variable    
(D)Relative 

• Rest mass energy of positron is

(A) 1.02 Mev  
(B) 0.51 Mev   
(C) 931 Mev    
(D) 1.2 Mev

• Number of neutrons in 235U are

(A) 92             
(B) 235            
(C) 143            
(D) 100

• Both Xenon and cesium each have isotopes

(A) 12             
(B) 33              
(C) 36              
(D) 39

• X -rays are similar in nature to

(A) Cathode Rays        
(B) Gamma rays          
(C) Positive rays          
(D) Alpha rays

• Mho m-1 is the unit of

(A) Resistance             
(B) Resistivity             
(C) Conductance         
(D) Conductivity

Inter (Part-II) Dera Ghazi Khan Board 2013
Physics
Part II(Subjective)
Time Allowed: 2.10 Hours 
Max. Marks: 83 

Section I

Q2 Write short answers any Eight (8) questions of the following                   16

• The potential is constant through out a given region of space. Is the electric field zero or non-zero in Otis region ? Explain
• Is E necessarily zero inside a charged rubber balloon Abe balloon is spherical ? Assume that charge is uniformly distributed over the surface
• Define 1 farad
• Write four differences between coulomb force and gravitational force
• Is it possible to orient a current loop in a uniform magnetic field such that the loop will not tend to rotate? Explain
• Why should resistance of an ammeter be very low
• Define magnetic flux. Is it a vector quantity
• What is magnetic flux through a plane surface of area 20 Cm2 , if it is held parallel to magnetic field B = 0.1 T inside the field
• show that Ԑ and  have the same unit
• When the primary of a transformer is connected to A.C, the current in it is very small if the secondary is open but increases when secondary is closed. Explain these facts
• Describe two methods by which magnetic flux through a closed circuit or loop can be changed
• Why are split rings used in D.C generator instead of slip rings?

Q3 Write short answers any Eight (8) questions of the following                   16

• Why the resistance of a conductor does rises with temperature
• Define ohmic and non ohmic devices
• Is the filament resistance lower or higher in a 500 W 229 V bulb than in a 100 W , 220 V bulb
• Name the derive that will (a) permit flow of direct current but oppose the flow of alternating current (b) Permit flow of A.0 but not D.0
• Define impedance. Write dorm its mathematical relation
• Explain the conditions under which electromagnetic waves are produced from a source
• Define ductile and brittle sub stances. Also give at least one example of each
• How can we obtain p-type and N-type substances from pure semi conductors ?
• Define stress and strain. Write also the units
• Write down the truth tables of 100 gate and AND gate
• Why is the base current in a transistor very small ?
• Why the photo diode is operated in reverse biased state?

Q4 Write short answers any Six (6) questions of the following                       12

• What advantages an electror microscope has over an optical microscope?
• What is a black body?
• Is it possible to create a single electron from energy
• Give two uses of X-rays in medical
• What are advantages of Easer over ordinary light?
• Define Half life of a element
• Define isotopes with two examples
• Why are heavy nuclei unstable
• What do you mean by the term critical mass

SECTION-II

Note: Attempt any Three questions from the section  8 x 3 = 2

Question #5.
(a)     Define electric field. Calculate the electric fled intensity due to an infinite sheet of charge at point close to the sheet
(b)        The resistance of an iron wire at 0 °C is 1 x104 Ω what is the resistance at 500°C if the temperature coefficient of resistance of iron is 5.2 x 10-3 K-1 ?

Question #6.
(a)     A coil of 0.1 m x 0.1 m and of 200 -ums carrying a current of 1.0 and is placed in a uniform magnetic field of 0.1 T . Calculate the maxim tin torque that acts on the coil
(b)        What is current generator? Drive at expression  sin(wt) for an A.0 generator

Question #7.
(a)     Explain RLC series resonance circuit. Also give its features
(b)        A 1.0 m long copper wire is subjected to stretching force and its length increases by 20 Cm. Calculate the tensile strain and percentages elongation which the wire undergoes

Question #8.
(a)     Describe the use of an operational amplifier as an inverting amplifier. Find an expression for its gain          5
(b)        What is the energy of a photon in a peam infrared radiation of wave length 1240 nm

Question #9.
(a)     How characteristic X-rays are obtained, Also give production of X-rays
(b)        Find the mass defect and the binding energy for tritium if the atomic mass of tritium is 3.0160494 mass of nutron is 1.008665 u and mass of proton is 1.007276 -u