CBSE Class 12 Physics Sample Paper 2014 Set B

1. 

The electric field lines in a region are shown in the figure. A and B are two points in the region. At which point a charge ‘+q’ experiences minimum force?

2. A distorted signal is received by a receiver set. Suggest a method to rectify this while doing the modulation process?

3. A current I flows through a wire of radius ‘r’ and the drift velocity ‘vd’. What is the drift velocity of electrons through a wire of same material but having double the radius, when a current ‘2I’ flows through it?

4. The figure shows a long straight conducting wire of circular cross section of radius ‘a’ (shaded portion) carrying a current I. Assume the current is uniformly distributed across this cross section. Draw the shape of the graph between magnetic field versus distance ‘r’ in the region between ‘a’ and ‘r’ if r > a.

5. In India domestic power supply is 220V, 50Hz; while in USA it is 110V, 50Hz.Give one advantage and one disadvantage of 220V supply over110 V supply.

6. The graph of variation of resistance R of a metal wire as a function of its diameter D is as follows. Give the reason for the shape of the graph.

7.An audio signal is not transmitted directly by converting it into an electromagnetic wave of same frequency. Give two reasons.

8. A magician during a show makes a concave glass lens with refractive index 1.47 changes into convex lens while dipping it in another medium. What will be the ratio of refractive index of glass with that of the medium?

9. A solenoid has a core of a material with relative permeability 400. The windings of the solenoid are insulated from the core and carry a current of 2A. If the number of turns is 1000 per metre, Calculate the magnetic intensity ‘H’ and the magnetic field ‘B’. 

10. The magnetic susceptibility for a specimen has a small negative value. To which class of the magnetic substances, does the specimen belong? What is Meissner effect?

11. Three resistors of resistance ‘r’ each are connected to get maximum possible resistance. Then they are connected differently to get minimum possible resistance. Find the ratio between minimum and maximum resistance so obtained.

12. A circular loop and a rectangular loop of wire are moving towards a uniform magnetic field region from a field free space with a constant velocity ’v’ with their plane perpendicular to the magnetic field. In which loop the induced emf is constant during the time of motion? What about the emf induced in the other one? 

Please refer to attached file for CBSE Class 12 Physics Sample Paper 2014 Set B