Name of the University : Netaji Subhas Open University
Name of the Exam : BDP Term End Exam
Document Type : Sample Question Paper
Year: 2016
Subject: Physics

Website : http://www.wbnsou.ac.in/student_zone...c2015-June2016
Download Model/Sample Question Papers:
EPH - I : http://www.indianjobtalks.com/uploads/76293-EPH-1.pdf
EPH - II : http://www.indianjobtalks.com/uploads/76293-EPH-10.pdf
EPH - III : http://www.indianjobtalks.com/uploads/76293-EPH-3.pdf
EPH - V : http://www.indianjobtalks.com/uploads/76293-EPH-5.pdf
EPH - VI : http://www.indianjobtalks.com/uploads/76293-EPH-6.pdf
EPH - VII : http://www.indianjobtalks.com/uploads/76293-EPH-7.pdf
EPH - IX : http://www.indianjobtalks.com/uploads/76293-EPH-9.pdf
EPH - X : http://www.indianjobtalks.com/uploads/76293-EPH-10.pdf

BDP Term End Physics Question Paper :
2nd Paper : Mechanics and General Properties of Matter
Time : 2 Hours
Full Marks : 50

1. Answer any two questions : 10 × 2 = 20
a) i) Show that areal velocity for a particle moving under the action of a central force is constant.
ii) Equation of motion for a planet in spherical polar co-ordinate is r l 1 = 1 ( ? cos ? + 1 ), where ? and l are constants. Change the equation to Cartesian system to show that the path described is an ellipse. 5 + 5
b) i) Derive the expression for gravitational potential at an external point of a thin spherical shell of radius R.
ii) Though Hydrogen, Helium are rarely found in the atmosphere of the Earth, but in the atmosphere of Jupiter their presence are substantial. Why ? 8 + 2

c) i) Show that if the radii of curvature at any point on the curved surface of a liquid be R and R l , the pressure difference between the two sides of the liquid surface is given by p = S ( 1/R, 1/R1 ) , where S is the surface tension of liquid.
ii) There is a hole of radius 0·2 mm at the bottom surface of a can. At what depth water will seep into the can ? ( Surface tension of water is 72 dynes/cm ).

d) i) Establish Poiseuille’s equation.
ii) From dimensional analysis derive Stokes’ law for viscous force.
iii) How does viscosity of a liquid change
with pressure and temperature ?

2. Answer any three questions : 6 × 3 = 18
a) i) Calculate the moment of inertia of a cylinder of radius R, length L and mass M, about the axis of the cylinder.
ii) A solid cylinder and a hollow cylinder of identical dimensions have been released from the top of an inclined plane of length L and angle of inclination ?. Which one will reach the bottom faster ? 3 + 3
b) i) If a central conservative force is given by Kr - n , n > 1, K is a constant, derive the expression for potential energy.
ii) Find the expression for the distance of closest approach for two identically charged particles with charge Q each and moving towards each other with a velocity v.

c) Discuss the elastic constants for a homogeneous solid and derive a interrelation amongst them. 6
d) Establish the equation of continuity. 6
e) i) One hollow rod with radii r1 and r2 ( r2 > r1 ), and another solid rod with radius r, have identical masses and length. They are of same material. The hollow rod is more rigid compared to the solid one. Why ?
ii) If there is no change in volume of a rubber string even after extension, what is its Poisson ratio ? 3 + 3
f) Calculate the depression at the mid-point of a light uniform beam supported at the ends and loaded at the centre.

3. Answer any four questions : 3 × 4 = 12
a) What is a conservative force ? Give an example. 2 + 1
b) If acceleration due to gravity in a certain region of space be uniform, show that the net gravitational torque on any two particles in that area with respect to a o-ordinate frame is zero. 3
c) What is Reynolds number ? What is the difference between Newtonian and Non- Newtonian liquid ? 1 + 2
d) A trolley of mass M is moving with a velocity v on a smooth rail. If due to heavy rains the open pot on the trolley catches water of mass m per second, what will be the change in velocity ?