Inter (Part-II) Bahawalpur Board 2015
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.

• The electrostatic forced between two charges is 42N. if we place a dielectric of €/r = 2.1 between the charges then the force become equal to :

(A) 42 N
(B) 88.2 N
(C) 20 N
(D) 2 N

• The effective way to increase the sensitivity of moving coil galvanometer is :

(A) Increase the area of coil
(B) increase the number of turns
(C) Increase the magnetic field
(D) Increase the value of constant C

• A battery more a charge of 40 C around a circuit constant rate in 20 sec. The current will be

(A) 2 A
(B) 0.5 A
(C) 80 A
(D) 800A

• Total Flux through a closed surface depends on

(A) Shape Surface
(B) Charge enclosed only
(C) Medium Only
(D) Charge and madium

• The unit of lagnetic Flux:

(A) N.mA^-1
(B) Nm ^-1A
(C) Nn^-1A^{- 1}
(D) NmA

• A pair of ( lark and Anti Quark makes a: 

(A) Meson
(B) Hardon
(C) Lepton
(D) Bryon

• β₂/2μ_⁰ is the expression of

(A) Lenz's Law
(B) Magnetic Energy
(C) Magnetic Energy Density
(D) Back emf

• A step up transformer is used 120 line to provide 240 v. If primary coil has 10 turns.The number turns in secondary is:

(A) 50
(B) 100
(C) 150
(D) 200

• In three phase voltage across any two lines is about:

(A) 220 v
(B) 230 v
(C) 400 v
(D) 430 v

• The gain of amplifier is given as:

(A) –βR_C/r_ie
(B) βr_ie/R_C
(C) –R₂/R₁
(D) 1+R₂/R₁

• The barrier potential of Silicon Diode at room temperature is: 

(A) 0.3 V
(B) 0.7 V
(C) 3 V
(D) 7 V

• A device tried to detect very weak magnetic field produced by brain is named as:

(A) MRI
(B) CAT Scans
(C) Squid
(D) CRO

• Using relativistic effects the location of an air craft after an hr flight can be predicted about:

(A) 20 m
(B)50 m
(C) 760 m
(D) 780 m

• The charge of an Alpha Particle is equal to:

(A) + e
(B) - e
(C) 2e
(D) -2 e

• The speed of an electron in nth orbit is given as:

(A) 4 π² Ke²/ nh
(B) 2 πKe²/nh
(C) 4 π Ke/n²h²
(D) 2 π²Ke²/nh

• In order to increase the K.E. of ejected photo electrons, there should be an increase in:

(A) Intensity Radiation
(B) Wavelength of Radiation
(C) Frequency of Radiation
(D) Both as B and C

• Circulation Blood can be studied by using Radioactive Isotope

(A) Cobalt - 60
(B) Phosphorus -32
(C) Sodium - 24
(D) Iodine - 131

Inter (Part-II) Bahawalpur Board 2015
Physics
Part II(Subjective)
Time Allowed: 2.10 Hours 
Max. Marks: 83 

Section I

2. Attempt any EIGHT short questions. (8 x 2 = 16)

• Show that an Ohm times Farad is equivalent o second.
• The potential is constant throughout a given region of space. Is the electrical filed zero or non-zero in the region? Explain.
• How can you identify that which plate of capacitor is positively charged?
• Is it possible to orient a current loop in a uniform magnetic field such that the loop will not tend to rotate?
• Suppose that a charge “q” is moving in a uniform magnetic field with a velocity. Why is there no work done by the magnetic force that acts on the charge?
• On what factors the included current due to motional emf depend?
• Is it possible to change both the area of the loop and the magnetic field passing through the loop and still have not induced emf in the loop?
• Can electric motor be used to drive an electric generator with the output from the generator being used to operate the motor.
• What is Lurentz Force? Give its formula.
• What are the function of Anodes in CRO?
• What is Photoconductor?

3. Attempt any EIGHT short questions. (8 x 2 = 16)

• What are the difficulties in testing whether he filament of a bulb obeys Ohm’
• Explain why the terminal potential difference of a battery decreases when the current drawn from it is increased?
• A sinusoidal current has rms value of 10A. What is its peak value?
• In a R-L Series Circuit, will the current lag or lead the voltage? Illustrate your answer by a vector diagram.
• Define Intrinsic Semi conductor and Extrinsic Semi Conductors.
• What is Net charge on a N-type or a P-type substance?
• What is the effect of Forwarded and Reverse biasing of a diode on the width of Depletion Region?
• Define B for Transistor. Also write its fundamental current equation.
• Define Kirchhoffs current Rule and Voltage rule.
• What is meant by A.M and F.M?
• Define super conductor. Give their two uses.
• What is meant by stain energy?

4. Attempt any SIX short questions. (6 x 2 = 12)

• What happens to total radiation from a black body if its absolute temperature is doubled?
• We do not notice the deBroglie Wavelength for a pitched cricket ball. Expalin why?
• Define Compton Effect. Write the formula of Compton shift for scattering angle.
• What factors make a fusion reaction difficult to achieve?
• If someone accidently swallows a source and b-source which would be the more dangerous to him? Explain why?
• What do we mean when we say that atom is excited?
• Define Hadrons and Leptons
• Define continuous Spectra and Line spectra?
• What are isotopes? Give an example.

Part-2

Question #5:
(a) State Gauss’s Law. Find Electric Intensity due to an infinite sheet of charged.
(b) 0.75A current flows through an iron wire when a battery of 1.5 V is connected across its ends the length of the wire is 5.0m and its cross sectional area is 2.5* 10.

Question #6
(a) What is Motional emf ? Derive and expression for motional emf.
(b) How fast must a proton more in a magnetic field of 2.50 * 10 T such that the magnetic force is equal to its weight.

Question #7
(a) Explain the passage of A.C through a capacitor in detail.
(b) A wire 2.5 m long and cross section area 10-5 m2 is stretched 1.5 mm by a force of 100 N in the elastic region. Calculate young’s modulus of the wire.

Question #8
(a) write a note on Heisenberg’s uncertainty principle.
(b) in a certain circuit the transistor has a collector current of 10 mA and base current of 40 HA. What is the current gain of the transistor? 

Question #9
(a) What is nuclear fission? Explain fission chain reaction and the controlled reaction in reactor.
(b) Compute the shortest wavelenght radiation in Balmer's Series. What value of n must be used?

Give answer any four question

Question #10 (a)

• Define specific resistance. Give its unit
• What do you mean by photoelectron
• What do you mean by Wheatstone bridge?
• What is stopping potential?
• What is diode? Give its one use.
• What is voltmeter?
• What is shunt resistance?
• Write down the truth table and symbol on AND Gate

(b) write down the procedure to find the resistance of wire by using slide wire bridge.
OR
Write down the procedure to study the characteristics of a semi conductor.

(Graph – A)

(i) Find the resistance from the graph
(ii)what does the graph represent ?

OR (Graph –B)

(i)Find the forward resistance between A and B.
(ii)what does the graph represent ?