(Collected from Previous Board Question Papers and CBSE Sample Papers andGuess Papers made by experienced teachers)
- Where does centre of curvature of a spherical mirror lie?
- Name two important properties of a magnet.
- How is 1 ohm related to ampere and volt?
- 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.
- Why is a series arrangement not used for connecting domestic electrical appliances in a circuit?
- Out of 60 W and 40 W lamps, which one has a higher electrical resistance when in use?
- 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
- What is meant by the term, ‘magnetic field’? Why does a compass needle show deflection when brought near a bar magnet?
- 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.
- (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?
- 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.
- Explain the cause of resistance offered by a conductor?
- 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.
- What is an ohmic resistor?
- What do you mean by principal focus and focal length of a concave mirror? Draw a diagram representing them.
- 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?
- (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 ? and 10 ? are connected in series, how does the current passing through the two resistors compare?
- 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.