COUNCIL OF HIGHER SECONDARY EDUCATION, MANIPUR

SAMPLE QUESTION, 1999

PHYSICS (THEORY)

 

Full Mark - 70

Pass Mark - 21

Time : 3  hours

 

The figures in the right margin indicate full marks for the questions

(i) There arc in all 33 questions. .All questions are compulsory.
(ii) Question Nos. 1to 10 are very short answer type questions carrying 1 mark each.
(iii) Question Nos. 11 to 19 are Short Answer type-II questions carrying 2 marks each.
(iv) Question Nos. 20 to 25 are Short Answer type-1 questions carrying 3 marks each.
(v) Question Nos. 26 to 29 are Long Answer (Essay) type questions carrying 5 marks each.
(vi) Question Nos. 30 to 33 are Multiple Choice type questions carrying 1 mark each. In these questions FOUR alternative answers are given, out of which only ONE is correct, Choose the correct answer and REWRITE it.
1. Define 'electro chemical equivalent' of an element. 1
2. Name a conductor disobeying Ohm's law. 1
 3.

What amount of work would have to be done in bringing a test change ‘q' from infinity along the perpendicular bisector of an electric dipole, up to a point distant ‘r' from the centre of the dipole ?

 1
4. What is a ferromagnetic substance ? 1
5. Define illuminating power' of a source of light. 1
6. At what distance from the face should a plane mirror be held so that a person of normal vision may see his/her own face most distinctly in the mirror ? 1
7.

Half life of radium is 1600 years. In how many years will an amount of radium reduce to 1/8 of its initial amount ?

  
8. Write one property of X-rays that is applicable to medical science. 1
9.

In one of Millikan’s oil-drop like experiment, an observer found the charges of two oil drops to be 4.8 X 10-19 C and 8'0 x 1 0-19C. Find, from the observation, the value of the electronic charge and the number of electrons in the first oil drop.

 ½+1/2=1
10. What is a rectifier?  
11. Show that two electric lines of force can not interact. 2
12. What is 'lightning’ ? How can a tall building be saved from the destructive action of lightning ? 1+2+2
13. Show that a current loop is equivalent to a magnetic dipole.  2
14. What is induced e.m.f. ? How is it produced? 1+1-2
15 Can sound waves pass through vacum ? Give reasons in support of your answer. 2
16 Show how you could convert a converging beam of light into a parallel beam.  2
17. Doppler's effect in light is symmetric. Justify the above statement. 2
18.

An electric field is applied perpendicular to the direction of a bunch of radio active radiations consisting of the three types of radiations emitted from a source. Show, in a diagram how will the radiations behave in presence of the electric field.

  2
19. Draw a neat is belled diagram to demonstrate photo electric effect.  2
20.

How are an ammeter and a voltmeter to be connected in an electrical circuit ? Why should an ammeter have a low resistance while a voltmeter, a high resistance.

 ½+1/2+1+1=3
21. How long will an electric kettle marked 500W-230V take to boil 1 litre of water initially at 200C, assuming that 20% of the electric energy goes waste ? 3
22. Prove that light waves are transverse. 3
23.

An instantaneous A. C. voltage is given by, E=10 sin (100?)t, where 'E' is in volts and 't’ is in second.Find the
 (i) peak value and
(ii) virtual value of the instantaneous voltage.
Find also the time period of the Oscillatory A. C.

 1+1+ 1= 3
24.

Show that an observer under water of refractive index n, at a depth h, looking Possibly upwards will see a circular hole of area ph2/n2-1 on the surface of the water,through which the observer will be able to see the outside world.

 3
25.

What amount of energy will be absorbed or liberated when an electron in the L-shell jumps to the K-shell in Bohr's model of atomic structure?
(Energy of the ground state of hydrogen atom= 13'6eV).

 3
26

Find an expression for the electric potential at a point in a medium of specific inductive capacity K due to a point charge.
Hence deduce an expression for the electric field intensity due to the point charge at the same point.
OR
Deduce an expression for the energy of a charged capacitor. In what form is the energy stored in the capacitor ?

 3+2=5
27.

Derive an expression for the force experienced by a current carrying conductor in a magnetic field.
For what angle of orientation of the conductor to the magnetic field, will the force be maximum ?
 OR
What is Blot -Savart's law of magnetic effect of electric ,current ? Deduce from the law, the definition of 1Tesla.

  4+1=5
28.

What is alternating current ? How is it generated ? In A.C. circuit, what substitutes the ohmic resistance in D.C. circuit ?
Why is it not possible to measure A.C. by a D.C. ammeter ?
OR
Describe the construction and action of an electrical machine in which electrical energy is transformed into mechanical energy.

 1+1+1+2=5
29. Describe the electronic bard theory of a crystalline solid.
OR
Describe how N-type and P-type semiconductors are formed. Name the dopant and majority carrier in each type of semiconductors you describe.
 		 5
30. Three equal resistances 6 Ohm each are connected to form the sides of an equilateral triangle. The resistance between any two terminal vertices is
(a) 18 ohm
(b) 9 ohm
(c) 4 ohm
(d) 2 ohm.
 		 1
31. A small needle of iron is suspended freely in the magnetic field of a bar magnet, The needle will experience
(a) a torque but no net force
(b) a net force but no torque
(c) both torque and net force
(d) neither torque nor net force		 1
32 Twilight is caused by the phenomenon of
(a) diffraction
(b) interference
(c) polarisation
(d) Scattering of light.		 1
33. For two different positions of an object, images of the same magnification can be produced by
(a) a convex mirror only
(b) a concave mirror only
(c) both convex and concave mirrors
(d) none of convex and concave mirross.
Given, m0= 4px 10-7 TmA-1		 1


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