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(Collected from Previous Board Question Papers and CBSE Sample Papers and Guess Papers made by experienced teachers)

1. Where does centre of curvature of a spherical mirror lie?
2. Name two important properties of a magnet.
3. How is 1 ohm related to ampere and volt?
4. Draw neat ray diagrams to illustrate the formation of images due to a beam of light incident parallel to the principal axis of a (i) concave mirror, (ii) convex mirror in each case.
5. Why is a series arrangement not used for connecting domestic electrical appliances in a circuit?
6. Out of 60 W and 40 W lamps, which one has a higher electrical resistance when in use?
7. Draw ray diagrams to represent the nature, position and relative size of the image formed by a convex lens for the object placed.(a) at F (b) Between F and O
8. What is meant by the term, 'magnetic field'? Why does a compass needle show deflection when brought near a bar magnet?
9. Two lamps, one rated 60W at 220 V and the other 40W at 220 V, are connected in parallel to the electric supply at 220V.

   (a) Draw a circuit diagram to show the connections.

   (b)Calculate the current drawn from the electric supply.

   (c)Calculate the total energy consumed by the two lamps together when they operate for one hour.

10. (a) Distinguish between the terms 'overloading' and 'short-circuiting' as used in domestic circuits.
    (b)Why are the coils of electric toasters made of an alloy rather than a pure metal?
11. A current of 0.5 A is drawn by a filament of an electric bulb for 10 minutes. Find the amount of charge that flows through the circuit.
12. Explain the cause of resistance offered by a conductor?
13. Define magnification of image formed by a lens. Derive the formula for magnification using image formation as given below:

    (i) Real image from a convex lens,

    (ii) Virtual image from a convex lens, and

    (iii) Virtual image formed by concave lens.

14. What is an ohmic resistor?
15. What do you mean by principal focus and focal length of a concave mirror? Draw a diagram representing them.
16. A current through a horizontal power line flows in east to west direction. What is the direction of magnetic field at a point directly below it and at a point directly above it?
17. (i) Draw a diagram to show, how two resistance R1 and R2 are connected in series?

    (ii) In a circuit if the two resistances of 5 Ω and 10 Ω are connected in series, how does the current passing through the two resistors compare?

18. A concave lens has focal length of 20 cm. At what distance from the lens a 5 cm tall object is placed so that it forms an image at 15 cm from the lens? Also, calculate the size of the image formed.