Physics
Lahore Board 2016
Inter Part-II
Group-I
Time:20 Min.
Objective Type
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.

• The sensitivity of galvanometer can be increased by:

(A) Decreasing the area of coil
(B) Decreasing the number of turns of Coil
(C) Increasing the magnetic filed
(D) Using a fine suspension

• The momentum of the moving photon is :

(A) zero
(B) ƛ/h
(C) hƛ
(D) h/ ƛ

• When the back emf in a circuit is zero, it draws :

(A) Zero current
(B) Maximum current
(C) Voltage and current
(D) Average current

• A Diode characteristic curve is plotted between :

(A) Current and time
(B) Voltage and time
(C) Voltage and current
(D) Forward voltage and reverse voltage

• Photocopier and inkjet printer are the application of:

(A) Electrostatics
(B) Magnetism
(C) Electricity
(D) Electro-magnettism

• In case of Capacity, the unit of reactance is:

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

• The building blocks of protons and neutrons are called:

(A) Ions
(B) Electrons
(C) Positrons
(D) Quarks

• All motions are:

(A) Neutrons
(B) Electrons
(C) Relative
(D) variable

• The number protons in any atom are always equel to the number of:

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

• If a change body is moved against the electric filed, it will again:

(A) P.E
(B) K.E
(C)Mechanical energy
(D) Electrical potential energy

• The phase angle between the voltage and current through resistor is :

(A) 0⁰
(B) 45⁰
(C) 180⁰
(D) 270⁰

• Balmer series lies in the:

(A) Ultraviolet region
(B) Far Ultraviolet region
(C) Infrared region
(D) Visible region

• Which type of impurity is to be added to a pure semi-conductor crystal to provide holes:

(A) Monovalent
(B) Trivalent
(C) Tetavalent
(D) Pentavalent

• Transistors are made from :

(A) Plastics
(B) Metals
(C) Insulators
(D) Doped semi-conductors

• The magnetic force is simply a:

(A) Reflecting force
(B) Deflecting force
(C) Restoring force
(D) Gravitational force

• An inductor may store energy in :

(A) Its magnetic filed
(B) Its electric filed
(C) Its coil
(D) A Neighboring circuit

• The brightness of the spot on cro screen is controlled by:

(A) Cathode
(B) Anode
(C) Grade
(D) Plates

 

Physics
Lahore Board 2016
Inter Part-II
Group - I
Time : 3.10 hrs
Essay Type
Marks = 83

Section – I

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

• Suppose that you follow an electric field line due to a positive point charge. Do electric field increase or decrease? Explain briefly.
• Describe the force or forces on a positive point charge when placed between parallel plates with similar and equal charges. Explain briefly.
• Do electrons tend to go to region of high potential or of low potential? Give reason.
• The time constant of series RC circuit is t = RC verify that an Ohm times farad is equivalent to second.
• Is it possible to orient a current loop will not tend to rotate? Explain briefly.
• How can a current loop be used to determine the presence of a magnetic field in a given region of space?
• Why the voltmeter should have a very high resistance?
• Write the two uses of cathode ray oscillosocope.
• Does the induced current depend on the resistance of the circuit? Explain briefly.
• How would you position a flat loop of wire in a changing magnetic field so that there is no emf induced in the loop?
• In a transformer, there is no transfer of charge from the primary to the secondary. How is then the power transferred?
•  What is meant by back motor effect in generators? Explain briefly.

3. Write short notes on any Eight (8) questions: (16)

• A potential difference is applied across the ends of a copper wire. What is the effect on drift velocity of free electrons by decreasing the length and the temperature of the wire?
• What are the difficulties in testing whether the filament of a lighted bulb obeys Ohm’s law?
• Wire four uses of photo diode.
• How the reception of a particular radio station is selected on your radio set?
• How does doubling the frequency affect the reactance of a capacitor?
• How many times per second will an incandescent lamp reach maximum brilliance when connected to a 50 HZ source/
• Distinguish between intrinsic and extrinsic semi conductor.
• Define modules of elasticity . Also give its unit.
• What is meant by strain energy?
• Why is the base current in a transistor very small?
• How does the motion of an electron in an n-type substances differ from the motion of holes in a p-type substances?

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

• Does the dilation mean that time really passes more slowly in moving system or that it only seems to pass more slowly. Explain briefly.
• What is wave particle duality? Give its one practical use.
• Why do not we observe a Compton effect with visible light?
• What is meant by a line spectrum? Explain how line spectrum can be used for the identification of elements.
• What are the advantages of lasers over ordinary light?
• What are isotopes? What do they have in common?
• A particle which produces more ionization is less penetrating. Why?
• Define background radiations. What are their sources?
• How can radio-activity help in the treatment of cancer?

Section-II
Note: Attempt any THREE questions.

5. (a) What is Wheatstone Bridge? How it is used to determine the unknown resistance ? 1,4

(b) A particle having a charge of 20 electrons on it falls through a potential difference of 100 volt. Calculate the energy acquired by it in electron volt. (3)

6. (a) How e/m of an electron can be determined? Explain. (5)

(b) A metal rod of length 25 cm is moving at a speed of 0.5 ms^-1 in direction perpendicular to a 0.25 T magnetic field. Find emf produced along the rod. (3)

7. (a) What are semi-conductors ? Discuss the formation of P-type and N-type materials with their Schematic diagram. (5)

(b) Find the capacitance required to construct a resonance circuit of frequency 1000 KHz? With an inductor of 5 mH. (3)

8. (a) What is the operational amplifier? Describe operational amplifier as investing amplifier. Calculate its gain. (5)

(b) A particle of mass 5.0 mg moves with the speed of 8.0 ms^-1. Calculate its Brogile wavelength. (3)

9. (a) State postulates of Borh’s model of the hydrogen atom and then show that  hydrogen atom have quantized radii. 2,3

(b) Find binding energy of the deuteron nucleus.

Mass of deuteron = 303435 x 10^-27 kg
Mass of proton = 1.6726 x 10^-27 kg
Mass of neutron = 1.6749 x 10^-27 kg

Section-III (Practical Part)
A. Attempt any four questions. (8)

• What is intensity of light?
• What is photo cell?
• Define capacitor.
• Define magnetic field.
• What is the use of transistor?
• Define forward and reverse bias.
• What is potentiometer?
• How a voltmeter is connected in a circuit?

B. Write the procedure to find the resistance of voltmeter By drawing graph between R and 1/V. (3)

OR

Write the procedure to determine the emf of a cell using potentiometer.

C. Answer the questions give below on the basis of following graph:

• What do you infer from the graph.
• Find the slope of the graph.
  (Image)

OR

• What do you infer from the graph?
• Find the slope of the graph.
  (Image)

Physics
Lahore Board 2016
Inter Part-II
Group-II
Time:20 Min.
Objective Type
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.

• A change particle enters in a strong magnetic field, its K.E:

(A) Remain constant
(B) Increases
(C) Decreases
(D) Increases and Decreases

• A PN-junction cannot be used as:

(A) Rectifier
(B) Amplifier
(C) Detector
(D) LED

• The mean value of A.C in a cycle is :

(A) 1
(B) 0
(C) 10
(D) 10/2

• Rest mass of photon is :

(A) Very small
(B) Very large 
(C) Zero
(D) Equal to rest mass of proton

• Two charges 1 µc and 5 µc separated by 20 cm, the ratio of electrical forces acting on them will be :

(A) 1:2
(B) 1:5
(C) 1:1
(D) 5:1

• Ka-x rays are produced due to transition of electrons from :

(A) K to L shell
(B) L to K shell
(C) M to K shell
(D) M to L shell

• A real transformer does not change :

(A) Voltage Level
(B) Current Level
(C) Frequency Level
(D) Power Level

• Curie temperature of iron is :

(A) 750k
(B) 500 k
(C) 1023 k
(D) 300 k

• In Pakistan, the frequency of A.C supply is :

(A) 100 Hz
(B) 50 Hz
(C) 220 Hz
(D) 60 Hz

• Selenium is :

(A) Insulator in light
(B) Insulator in dark
(C) Conductor in dark
(D) Semiconductor in dark

• The moderator used in a nuclear reactor is:

(A) Sodium
(B) Uranium
(C) Graphite
(D) Cadmium

• The power factor of RL-series circuit is:

(A) 0
(B) 1
(C) less then 1
(D) more then 1

• The quantity h/m0c has the dimensions of :

(A) Length
(B) Time
(C)Mass
(D) Energy

• The ratio of potential barriers of Ge to Si at room temperature is:

(A) 7:3
(B) 1:3
(C) 2:5
(D) 3:7

• The galvanometer can be made sensitive by making the factor BAN/C:

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

• The activity of radioactive sample:

(A) Is constant
(B) Increases with time
(C) Decreases linearly with time
(D) Decreases exponentially with time

• Heat generated by a 40 W bulb in one hour is :

(A) 140 j
(B) 1440 j
(C) 14400 j
(D) 144000 j

Physics
Lahore Board 2016
Inter Part-II
Group - II
Time : 3.10 hrs
Essay Type
Marks = 83

Section – I

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

• State Gauss’s law. Write down its mathematical expression.
• Write down two differences between gravitational force and coulomb’s force.
• Suppose that you follow an electric field line due to positive point charge. Do electric field and the potential increase or decrease?
• Describe the force or forces on a positive point charge when placed between parallel plates with similar and equal charges.
• How can you convert a galvanometer into a voltmeter?
• What should be the orientation of current carrying coil in a magnetic field so that torque acting upon the coil is: (a) maximum, (b) minimum?
• How can a current loop be used to determine the presence of a magnetic field in a given region of space?
• If a charged particle of charges ‘q’ is moving in a region with velocity v where ther is an electric field E and magnetic field B, find total force on the paricle?
• Write down four factors on which mutual inductance depends.
• Distinguish between slip rings and split rings.
• Four unmarked wires emerge from a transformer. What steps would you take to determine the turns ratio?
• Can a D.C motor be turned into a D.C generator?
• What changes are required to be done?

3. Write short notes on any Eight (8) questions: (16)

• Why does the resistance of a conductor rise with temperature?
• Do bends in wire affect its electrical resistance? Explain.
• What is rheostat? Write its one use.
• A sinusoidal current has rms value of 10A. What is peak value or maximum value?
• Define choke. What is its use?
• What is meant by A.M and F.M?
• What is meant by hysteresis loss?
• Distinguish between amorphous and polymeric solids.
• Define stress and strain.
• What is net charge on a n-type or p-type substance?
• Why ordinary silicon diodes do not emit light?
• Why a photodiode is operated in reverse biased state?

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

• Can pair production take place in vacuum? Explain.
• Is it possible to create a single electron from energy? Explain.
• If the speed of light were infinite, what would the equations of special theory of relatively reduce to?
• Why population inversion and lasing action are necessary for Laser production?
• What is meant by Cat-Scanner?
• What is biological effect of X-rays?
• How can radioactivity help in the treatment of cancer?
• What factors make a fusion reaction difficult to achieve?
•  A particle which produces more ionization is less penetrating. Why?

Section-II
Note: Attempt any THREE questions.

5. (a) Define electric potential. Derive the expression for electric potential at a certain point due to a point charge. (5)

(b)A rectangular bar or iron is 2.0 cm by 2.0 in cross section and 40 cm long. Calculate its resistance if the resistivity of iron is 11 x 10^-8 Ωm. (3)

6. (a) Describe how charge to mass (e/m) ratio of an electron can be determined by projecting its perpendicular to a magnetic field. (5)

(b) A coil of 10 turns and 35 cm² area is in a perpendicular magnetic field of 0.5 T. The coil is pulled out of the field in 1.0 sec. Find the induced e.m.f in the coil as it is pulled out of the field. (3)

7. (a) Explain RC series circuit. Find its impedance and draw its impedance diagram. (5)

(b) A 1.0 m long copper wire is subjected to stretching force and its length increase by 20 cm. Calculate percentage elongation which the wire undergoes. (3)

8. (a) What is wave nature of particles? How Davison and Germer experiment confirmed it? 2,3

(b) The current following into the base of transistor is 100 μ A. Find its collector Current lc its emitter current l _E and the ratio l _C / l _{E ,} if the value of current gain ß is 100. (3)

9. (a) Define isotopes and describe mass spectrograph to separate different isotopes of an element. (5)

(b) Compute the shortest wavelength radiation in the Balmer series. What value of “n” must be used? (3)

Section-III
(Practical Part)

A. Attempt any four questions. (8)

• What is unit of current? Define it.
• What is shunt resistance? Write its units.
• Is it possible that a source of emf has greater terminal potential difference than its emf? If yes or no, give reason?
• Why the deflection of galvanometer is zero at balance point on the wire of potentiometer?
• Draw the circuit diagram to find the internal resistance of galvanometer by half deflection method.
• Draw truth table and symbol of OR and NOT gate.
• What is meant by threshold frequency? Write its unit.
• What is Ohm’s law? Write formula.

B. Write down the procedure of experiment to find the internal resistance of cell using a potentiometer. (3)

OR

Write down the procedure of experiment to study the relation between current and capacitance when different capacitors are used in AC circuit.

C. Answer the questions given below on the basis of following graph:

Graph A:

• What do you infer from the graph?
  
• Find the slope of the graph.