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#1 DEADLYDOCTOR Senior Member Join Date: Sep 2009 Location: R.I.P(Rest In Peace) Posts: 742 Thanks: 0 Thanked 1,143 Times in 374 Posts     Physics Paper 2010

Physics Paper 2010
Paper 1
Part II

Q.2 a) define a scalr field,obtain an expression for the Gradient of a scalar field. Why the gradient of a scalar field is vector?

b) Given phi (x,y,z) = X2yz3 (x square y z cube)

c) for what values of 'a' ,the vector A = 2i+aj+k and B= 4i -2j-2k are perpendicular.

Q.3 a) Distinguish between Linear and Angular momentum. Explain the law of conservation of angular momentum. Prove that the Angular momentum is constant in the absence of external torque.

b) The angular momentum J ps a particle is given as kj = 8 t powers 4 i- 2 t square j + 12 t cube k. find the torque at t=1

Q.4 a) Discuss in detail the relativity of mass, time and length.
b) What is time dilation? Explain with example.
c) When we say that a clock in moving frame runs slower than a clock in a stationary frame. What does it mean?

Q.5 a) Differentiate between streamline and turbulent motion of a liquid.
b)What is" coefficient of viscosity"? Explain in detail the Stoke's Law applicable in determining the coefficient of viscosity of a viscous liquid experimentally.
c) Why do auto manufactures recommend using different viscosities of engine oil in cold and hot climate,

Q.6 a) what is polarization of light? Explain Polarization by reflection and obtain Brewstar Law. Also explain the idea of double reflection.
b) We wish to use a Quartz sheet (n=1.54) in air as polarizer. Find the polarizing angle and angle of refraction.

Q.7 a) Define internal energy. State and explain First and Third laws of thermodynamics.
b) what is heat engine ?Determine the efficiency of the engine if it takes 10,000 J of heat and delivers 2000 J of work per cycle.

Q.8 write note on any TWO:
i) centre of mass
ii) diffraction grating and Resolving Power
iii)Production of low temperature.
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#2 DEADLYDOCTOR Senior Member Join Date: Sep 2009 Location: R.I.P(Rest In Peace) Posts: 742 Thanks: 0 Thanked 1,143 Times in 374 Posts     Physics Paper 2010
Paper 2
Part II

Q.2 a) State and prove Gauss's law in electrostatics and express the law in differential forms.
b) Find the electricity intensity at a point outside a volume distribution of charge confined into a spherical region of radius R.

Q.3 a) State and explain Ampere's law . Derive an expression for the value of 'B' inside a solenoid.
b) a thin 10 cms long solenoid has a total of 400 turns of wire and carries a current of .20 ampere. Calculate the field inside near the centre.(given μ0 = 12.57 *10 powers-7 T-m/A )

Q.4 a How a semi conductor diode is used as a half wave and full wave rectifier?
b) What are the transistors? Give construction and symbol of PNP and NPN transistor.
c) The resistivity of a metal increases with increase in temperature while that of a semi conductor decreases. Explain

Q.5Discuss briefly the wave number of matter and obtain an expression of de Broglie's wavelength for matter waves.
b) calculate de Broglie's wavelength of a .20 kg ball moving with a speed of 15m/s.

Q.6 a) Derive Einstein's photoelectric effect on the basis of quantum theory and derive Einstein's Photoelectric equations.
b) calculate the work function of NA in electron volts given that the threshold wavelength is 6800. 6.625 * 10-34 J-S

Q.7 a)Define the terms decay constant ,half life and average life as applied to a radioactive substance. Find the relation between them.
b)The half life of radium is 1590 years . In how many years will one gm of pure element
i) lose one centigram
ii) be reduced to one centigram

c) Whena nucleus emitsa gamma ray photon ,what happens to its atomic number and its actual mass.

Q.8 Write notes on any Two:
a) self and mutual inductance
b) Pauli's Exclsusion Principle
c) Compton Scattering
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#3 Last Island Royal Queen of Literature Join Date: May 2005 Location: Forest of Fallen Stars Posts: 7,585 Thanks: 2,425 Thanked 15,842 Times in 5,005 Posts            Paper I

PART – I (MCQ)
(COMPULSORY)

Q.1. Select the best option/answer and fill in the appropriate box on the Answer Sheet. (20)

(i) If A= 6i-8j, then 4A has the magnitude:
(a) 40
(b) 10
(c) 20
(d) None of these

(ii) Let A= 2i+6j-3k and B= 4i+2j+k then A.B equals:
(a) 8i+12j-3k
(b) 17
(c) 23
(d) None of these

(iii) If V is an operator, then V.V means:
(a) Gradient of a Scalar field
(b) Curl of a vector field
(c) Divergence of a Vector field
(d) None of these

(iv) The volume of a parallelepiped bounded by Vectors A,B and C can be obtained from the expression:
(a) ( A x B ).C
(b) (A.B)x C
(c) ( A x B ) x C
(d) None of these

(v) A force acting on a particle is conservative if:
(a) It obeys Newton's third law
(b) It obeys Newton's second law
(c) It works equals the change in Kinetic energy
(d) None of these

(vi) A torque applied to a rigid object always tends to produce:
(a) A rotational acceleration
(b) A linear acceleration
(c) Precision
(d) None of these

(vii) When the velocity of a body is constant, its acceleration is:
(a) Maximum
(b) Zero
(c) Infinity
d) None of these

(viii) In the absence of external torque the total angular momentum is:
(a) Constant
(b) Zero
(c) infinity
(d) None of these

(ix) The rate of change of Momentum of the particle is:
(a) Energy
(b) Force
(c) Impulse
(d) None of these

(x) Constructive and destructive superposition of waves is observed in:
(a) Polarisation
(b) Interference
(c) Diffraction
(d) None of these

(xi) The intensity of a wave is proportional to the square of:
(a) Amplitude
(b) Time
(c) Intensity
(d) None of these

(xii) The colours in soap bubbles, oil slick etc. in a thin film is due to:
(a) Diffraction
(b) Polaristaion
(c) Interference
(d) None of these

(xiii) For higher resolution, in a diffraction grating, one needs to have:
(a) Large number of ruling
(b) Small number of ruling
(c) No rulings at all
(d) None of these

(xiv) To produce interference, the sources must be:
(a) Intense
(b) Incoherent
(c) Coherent
(d) None of these

(xv) Interference fringes are of:
(a) Unequal width
(b) Equal width
(c) Variable width
(d) None of these

(xvi) A Carnot Cycle is:
(a) a rectangle on a P-V graph
(b) bounded by two isotherms and two adiabatics
(c) any four sided process on a P-V graph
(d) None of these

(a) The temperature of the system remains constant
(b) The temperature of the system must change
(c) The internal energy

(xviii) A Carnot Cycle heat engine operates between 227°C and 127° C. Its efficiency is:
(a) 44%
(b) 20%
(c) 79%
(d) None of these

(xix) Metals pipe carrying water some times bursts in winter because:
(a) Water expands
(b) Ice expands when melts
(c) Metal contracts more than water
(d) None of these

(xx) A Fahrenheit thermometer and Celsius thermometer shows the same reading at:
(a) 200°
(b) -40°
(c) 100°
(d) None of these
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#4 Last Island Royal Queen of Literature Join Date: May 2005 Location: Forest of Fallen Stars Posts: 7,585 Thanks: 2,425 Thanked 15,842 Times in 5,005 Posts            Paper II __________________
The Me you have always known, the Me that's a stranger still.
#5 bear Senior Member Join Date: Jun 2010 Location: لاہور Posts: 109 Thanks: 54 Thanked 93 Times in 50 Posts  PHYSICS PAPER 1 IN .pdf

PHYSICS PAPER 2 IN .pdf
#6 very special 1 Senior Member Join Date: Dec 2010 Location: dream land,where eagles live Posts: 441 Thanks: 484 Thanked 286 Times in 195 Posts    plz check and correct
1 a
2 b
3 c
4d
5 c
6 a
7 b
8 a
9 b
10 b
11 a
12 c
13 a
14 c
15 b
16 b
17 b
18 b
19a
20 b

Paper 2 objective
1 b
2 c
3 c
4 c
5 d confuse
6 b
7 a
8 b
9 c
10 d
11 b
12 a
13 b
14 a
15 c
16 a
17 b
18
19a
20 c
#7
 Ali Hassan kazmi Member Join Date: Oct 2009 Location: lahore Posts: 21 Thanks: 8 Thanked 9 Times in 8 Posts  some of ur answer are corrected as

paper 1

Q4. A

Q12. d or c both are possible (because the process in which no heat enter or leave )

Paper 2

Q1. C

Q5. A

Q18. C
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