CBSE Class 12 Physics Question Paper Foreign with answers 2017 Set 02

CBSE Class 12 Physics Question Paper Foreign with answers 2017 (2). 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. A photosensitive surface emits photoelectrons when red light falls on it. Will the surface emit photoelectrons when blue light is incident on it ? Give reason.

2. Draw logic symbol of an OR gate and write its truth table.

3.Write the expression for speed of electromagnetic waves in a medium of electrical permittivity ε and magnetic permeability μ.

4. Does the magnifying power of a microscope depend on the colour of the light used ? Justify your answer.

5. Two metallic wires P and Q of the same material and same length but different cross-sectional areas A1 and A2 are joined together and then connected to a source of emf. Find the ratio of the drift velocities of free electrons in the wires P and Q, if the wires are connected (i) in series, and (ii) in parallel.

6. Distinguish between broadcast mode and point-to-point mode of communication and give one example for each.

7. Use the mirror equation to show that an object placed between f and 2f of a concave mirror forms an image beyond 2f.

OR

(a) State the condition under which a large magnification can be achieved in an astronomical telescope.

(b) Give two reasons to explain why a reflecting telescope is preferred over a refracting telescope.

8. Find the intensity at a point on a screen in Young’s double slit experiment where the interfering waves of equal intensity have a path difference of (i) λ/4, and (ii) λ/3.

9. Write two points of difference between n-type and p-type semiconductors. 

10. Define electric flux. Write its SI unit.

Using Gauss’s law, deduce an expression for electric field intensity due to an infinitely long straight uniformly charged wire.

11. A proton and an α-particle move perpendicular to a magnetic field. Find the ratio of radii of the circular paths described by them when both (i) have equal momenta, and (ii) were accelerated through the same potential difference.

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