Electricity
1. Explain the importance of fossils in organic evolution.
2. Draw linear diagram to obtain ratio of F2 progeny as a result of crossing between tall pea plant ( dominant ) with short pea plant ( recessive ).
3. Why is hypermetropia caused ? How can it be corrected ?
4. Draw circuit diagram of three resistances connected in series combination. Derive formula for equivalent resistance for this combination.
5. State Snell’s law for refraction of light. A concave mirror forms two times magnified and real image of an object placed at 15cm from its pole. Determine the distance of image from mirror and focal length of the mirror.
6. A wire of a given material having length and area of cross-section A has a resistance 8 Ω. Determine the resistance of another wire of same material having length and area of cross-section ?
7. Define prism angle and angle of deviation for a prism. Write the sequence of colours in the spectrum formed by the passage of white light through a prism. Explain the process of formation of rainbow.
8. Write the relation between object distance ( u ), image distance ( v ) and focal distance ( f ) of a spherical lens. What is magnification ?The refractive index of glass with respect to air is and the refractive index of water with respect to air is . If the speed of light in air is , find the speed of light in (a) glass, (b) water.
9. A charge of 300 C is drawn by a filament of an electric bulb for 5 minutes. Find the amount of electric current flowing through the circuit.
10. Define the principal focus of a concave mirror. Write two uses of a convex mirror.
11. State Ohm’s law. Describe an experiment to verify this law.
12. Two lamps one rated 60 W, 220 V and the other 40 W, 220 V are connected in parallel to a 220 V electric supply mains. What is the total current drawn from the electric mains if the voltage of electric supply is 220 V ?
13. a) Define the power of lens. b) Draw a ray diagram for formation of image of an object situated at a point in between 2 f 1 and f 1 distances from the optical centre of the concave lens and write the nature of the image formed. c) What happens when light is falling perpendicular by to an interface of two media?
14. Name the two major defects of an eye. Explain causes of their development and discuss methods of their correction.