CBSE Class 12 Physics Delhi Question Paper 2013 (1)

CBSE Class 12 Physics Delhi Question Paper 2013 (1). Students can download the last year question papers using the link below. Free download of examination question papers with solutions.Last 10 year question papers should be practised to get better marks in examinations. 

1.(i) Draw the graphs showing variation of inductive reactance and capacitive reactance with frequency of applied a.c. source.

    (ii) Can the voltage drop across the inductor or the capacitor in a series LCR circuit be greater than the applied voltage of the a.c. source ? Justify your answer. 

2. The image of a candle is formed by a convex lens on a screen. The lower half of the lens is painted black to make it completely opaque. Draw the ray diagram to show the image formation. How will this image be different from the one obtained when the lens is not painted black ? 

3. An electric dipole is held in a uniform electric field. (i) Using suitable diagram, show that it does not undergo any translatory motion, and (ii) derive an expression for the torque acting on it and specify its direction. 

4. A galvanometer with a coil of resistance 120 ohm shows full scale deflection for a current of 2.5 mA. How will you convert the galvanometer into an ammeter of range 0 to 7.5 A ? Determine the net resistance of the ammeter. When an ammeter is put in a circuit, does it read slightly less or more than the actual current in the original circuit ? Justify your answer.  resistivity of a conductor in terms of number density of free electrons and relaxation time. 

                                                     OR

State the principle of potentiometer. Draw a circuit diagram used to compare the e.m.f. of two primary cells. Write the formula used. How can the sensitivity of a potentiometer be increased ?

5. Explain, with the help of diagram, the principle and working of an a.c. generator. Write the expression for the e.m.f. generated in the coil in terms of its speed of rotation. 

6. Give reasons for the following : 

(i) Long distance radio broadcasts use short-wave bands.

(ii) The small ozone layer on top of the stratosphere is crucial for human survival.

(iii) Satellites are used for long distance TV transmission.

7. A figure divided into squares, each of size 1 mm2, is being viewed at a distance of 9 cm through a magnifying lens of focal length 10 cm, held close to the eye.

(a) Draw a ray diagram showing the formation of the image.

(b) What is the magnification produced by the lens ? How much is the area of each square in the virtual image ?

(c) What is the angular magnification of the lens ? 

Please click the link below to download pdf file of CBSE Class 12 Physics Delhi Question Paper 2013 (1).