1. Velocity time graph of a body is shown in the diagram below.
   
   What conclusion can be drawn about the velocity of the body from the graph?
2. The value of G on earth’s surface is 6.67 x 10 -11 Nm2/kg2. What is its value on the surface of moon?
3. A person weighs 600N on the surface of earth. Find his weight and mass on the surface of earth. Take g = 10 m/s2
4. Derive the relation between force and acceleration. Define the unit of force.

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COMMUNICATION SYSTEMS

Max. Marks :: 30 Time:: 75 minutes

1 mark questions

1. Define bandwidth of a signal.
2. Define modulation index.
3. What is the function of a modem?
4. Why is short wave band used for long distance transmission?
5. Name the type of modulation prefered for digital communication.
6. Draw diagram to represent a digital signal and an analogue signal.
7. What do you mean by sampling of signal?
8. Name the appropriate communication channel needed to send a signal of band width 100 kHz over a distance of 8 km.2 Marks Questions
9. Derive an expression for the maximum distance up to which TV signals can be transmitted using a transmitting antenna of height h.
10. Distinguish amplitude modulation and amplitude modulation.
11. Draw a block diagram of a simple amplitude modulation system and explain briefly how amplitude modulation is achieved.
12. What is the need for modulating a message signal for long distance transmission?3 marks questions
13. 5 Marks Questions

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1. State the Principle of a cyclotron
2. Calculate the range of an ammeter of resistance 24 ohms and can allow a maximum current of 500mA through its coil, when shunted by a resistance of 3 ohms.
3. Write the dimensional formula of μ0
4. Define 1 ampere as defined in SI (based on force between two straight parallel conductors of infinite length)
5. State Fleming’s left hand rule.
6. State the principle of a moving coil galvanometer
7. Why a cyclotron cannot be used to accelerate electrons.
8. Write the resistance of (a) an ideal ammeter (b) an ideal voltmeter.

   2 Marks Questions

9. Derive an expression for cyclotron frequency.
10. Write the difference between paramagnetism and ferromagnetism
11. State the factors affecting the strength of an electromagnet.
12. Calculate the magnetic moment of the electron in the ground state of hydrogen atom.

    3 marks questions

13. State Ampere’s circuital law and apply it to find the magnetic field inside a torroid.
14. Discuss the equivalence of a bar magnet and a current carrying solenoid.
15. What are the magnetic elements of earth. Define each.

    5 Marks Questions

16. State Biot Savart law and apply it to find the magnetic field at a point on the axis of a circular loop carrying current.

1. The drift velocity is of the order of a few cm/s. But when we switch on a bulb, it glows instantly. How is this possible?
2. Define internal resistance.
3. If n identical resistors are connected in series first and then in parallel, Calculate the ratio of effective resistance in series to the effective resistance in parallel.
4. Define mobility.
5. State Ohm’s law.
6. State the principle of a potentiometer.
7. Write the colour coding of a carbon resistor of resistance 18000 Ω and a tolerance 10%
8. What is a thermistor?

   2 Marks Questions

9. Deduce Ohm’s law using the concept of drift velocity.
10. State Kirchhoff’s laws for electric networks.
11. Distinguish emf and terminal voltage.
12. Derive an expression for drift velocity.

    3 marks questions

13. A battery om emf E and internal resistance r gives a current 0.5 A with an external resistance of 12 Ω and a current 0.25 A with an external resistance of 25Ω. Calculate the internal resistance and emf of the cell.
14. An electric motor operating on a 50 V dc supply draws a current of 12A. If the efficiency of the motor is 30%, estimate the resistance of the windings of the motor.
15. Draw the diagram showing the experimental arrangement for determining the resistance of a given wire of unknown resistance.

    5 Marks Questions

16. (a)Explain how a potentiometer is used to determine the internal resistance of a primary cell.

    (b)State the factors affecting the internal resistance of a cell

Max. Marks :: 30                                      Time:: 75 minutes

1 mark questions

1. Define electric potential.
2. Define 1 farad.
3. State the principle of a capacitor.
4. Draw the equipotential surface for a point charge q>0.
5. Define dielectric constant of a medium on the basis of capacitance.
6. Write the ratio of electric potential at a distance r on equatorial position to the electric potential at a distance r on axial position.
7. Calculate the radius of a spherical conductor of capacitance 1 pF.
8. What is electrostatic shielding?2 Marks Questions
9. A regular hexagon of side 10 cm has a charge 5 μC at each of its vertices. Calculate the potential at the centre of the hexagon.
10. Derive an expression for the energy stored in a capacitor.
11. Four capacitors are connected as shown in diagram. Calculate the equivalent capacitance between the points X and Y.
    
12. When two capacitors of capacitance C₁ and C₂ are connected in series, the net capacitance is 3μF . When connected in parallel the effective capacitance is 16μF. Calculate the values of C₁ and C₂3 marks questions
13. Derive an expression for the capacitance of a parallel plate capacitor with a dielectric slab of thickness less than the spacing between the the plates inserted between the plates.
14. A 10μF capacitor is charged by a 30V dc supply and then connected across a an uncharged 50μF capacitor. Calculate (i) the final potential difference across the combination, and (ii) the initial and final energies. How will you account for the difference in energy?
15. A parallel plate capacitor with air between the plates has a capacitance of 8 pF. What will be the capacitance if the distance between the plates is reduced by half and the space betwee them is filled with a substance of dielectric constant K = 6?5 Marks Questions
16. Describe the principle construction and working of a Van de Graff generator. Explain why the apparatus is enclosed inside a steel chamber maintained at high pressure.