Here I am sharing the Physic Question paper of Karnataka Board Pre University

**MODEL QUESTION PAPER-I**

PART A
I Answer the following. 10 x 1 = 10

1. Draw the electric lines of force in the case of two positive point charges

separated by a small distance.

2. Name the charge carriers in metallic conductors.

3. A coil perpendicular to a uniform magnetic field is rotated by 1800. What is

the change in the flux through it?

4. Write the expression for displacement current.

5. Mention one common method of generating X-rays.

6. Write the expression for magnifying power of a telescope in terms of focal

lengths.

7. What is the outcome of Davisson Germer experiment?

8. How does nuclear radius of an atom depend on its mass number?

9. Who discovered the phenomenon of photoelectric effect?

10. What is demodulation?

**PART – B**
II Answer any FIVE of the following questions. 5×2=10

11. Write two properties of an electric charge.

12. What is electrostatic shielding? Mention its one application.

13. State Kirchhoff’s rules of an electrical network.

14. Mention two properties of a diamagnetic material.

15. What are eddy currents? Mention one application of eddy currents.

16. Draw the ray diagram to construct an image when an object is placed

between the principal focus and pole of a concave mirror.

17. Mention two necessary conditions for doping.

18. Draw the block diagram of a generalized communication system.

**PART – C**
III Answer any FIVE of the following questions. 5×3=15

19. Write the expression for electric potential at a point due to a dipole and

hence arrive at the expression for electric potential at a point on the dipole

axis.

20. Obtain the expression for effective capacitance of three capacitors connected

in parallel.

21. What is a cyclotron? Draw its schematic labeled diagram.

22. Explain briefly the coil-magnet experiment to demonstrate the phenomenon

of electromagnetic induction.

23. What is meant by alternating current? Define its amplitude and time period.

24. Using Huygen’s wave theory of light, show that the angle of incidence is equal

to angle of reflection in case of reflection of a plane wave by a plane surface.

25. Mention three experimental observations of photoelectric effect.

26. Classify metals, semiconductors and insulators based on the band theory of

solids.

**PART – D**
IV Answer any TWO of the following questions. 2×5=10

27. Obtain the expressions for effective emf and effective internal resistance

when ‘n’ different cells are connected in parallel.

28. State and explain Biot-Savart’s law and write its mathematical equation in

vector form.

29. Assuming the expression for magnetic field at a point on the axis of a circular

current loop, show that a long current carrying solenoid acts as a bar magnet.

V Answer any TWO of the following questions. 2×5=10

30. Derive the expression for the refractive index of the material of a prism in

terms of the angle of the prism and angle of minimum deviation.

31. State radioactive decay law. Show that t

oe N N l - = for a radioactive element

with usual notations.

32. What is a solar cell? Explain its working with a diagram and draw the I -V

characteristics.

VI Answer any THREE of the following questions. 3×5=15

33. The electrostatic force on a metal sphere of charge 0.4 mC due to another

identical metal sphere of charge - 0.8 mC in air is 0.2N. Find the distance

between the two spheres and also the force between the same two spheres

when they are brought into contact and then replaced in their initial

positions.

34. In the given circuit, calculate the (i) effective

resistance between A and B (ii) current through

the circuit and (iii) current through 3 W resistor.

35. A resistor, an inductor and a capacitor are connected in series with a 120V,

100Hz ac source. Voltage leads the current by 350 in the circuit. If the

resistance of the resistor is 10W and the sum of inductive and capacitive

reactances is 17W, calculate the self-inductance of the inductor.

36. A beam of light consisting of two wavelengths 500 nm and 400 nm is used to

obtain interference fringes in Young’s double slit experiment. The distance

between the slits is 0.3 mm and the distance between the slits and the screen

is 1.5 m. Compute the least distance of the point from the central maximum,

where the bright fringes due to both the wavelengths coincide.

37. The first member of the Balmer series of hydrogen atom has wavelength of

656.3nm. Calculate the wavelength and frequency of the second member of

the same series. Given, C = 3×108 m/s.

**Address:**
Pre University Education Board

18th Cross Rd, Malleswaram, Bangalore, Karnataka

080 2344 6475

**Map:**