Name of the Board : CBSE Academic
Class : XII STD
Subject : Physics
Year : March 2016
Website : http://cbseacademic.in/SQP_CLASSXII_2015_16.html
Download Sample Question Paper : https://www.pdfquestion.in/uploads/8089Physics.pdf
Download Marking Scheme : https://www.pdfquestion.in/uploads/8089PhysicsMS.pdf
Physics Sample Question Paper :
Time Allowed : 3 Hours
Maximum Marks : 70
Related : CBSE Academic Class XII Mathematics Sample Question Paper 2015-16 : www.pdfquestion.in/8084.html
General Instructions :
1. All questions are compulsory. There are 26 questions in all.
2. This question paper has five sections: Section A, Section B, Section C, Section D and Section E.
3. Section A contains five questions of one mark each, Section B contains five questions of two marks each, Section C contains twelve questions of three marks each, Section D contains one value based question of four marks and Section E contains three questions of five marks each.
4. There is no overall choice. However, an internal choice has been provided in one question of two marks, one question of three marks and all the three questions of five marks weightage. You have to attempt only one of the choices in such questions.
Section A :
1. Figure shows a point charge +Q, located at a distance R/2 from the centre of a spherical metal shell. Draw the electric field lines for the given system. (1)
2. Give an example of a material each for which temperature coefficient of resistivity is (i) positive, (ii) negative. (1)
3. A device ‘X’ is connected to an a.c. source V = Vo sin ?t. The variation of voltage, current and power in one complete cycle is shown in the following figure. (1)
(i) Which curve shows power consumption over a full cycle?
(ii) Identify the device ‘X’.
4. An object is placed in front of convex lens made of glass. How does the image distance vary if the refractive index of the medium is increased in such a way that still it remains less than the glass? (1)
5. Name the network within an institution, made by connecting all or some of their computers.
Section B :
6. Two cells of E.M.F. 10 V and 2 V and internal resistances 10 O and 5 O respectively, are connected in parallel as shown. Find the effective voltage across R.
7. Figure shows a system of two polarizing sheets in the path of initially unpolarized light. The polarizing direction of first sheet is parallel to x-axis and that of second sheet is 60o clockwise from x-axis. Calculate what fraction of intensity of light emerges from the system. State Huygen’s principle. Using it, construct a ray diagram for a plane wave front getting incident on a denser medium. (2)
8. A monochromatic light source of power 5mW emits 8X1015 photons per second. This light ejects photoelectrons from a metal surface. The stopping potential for this set up is 2V. Calculate the work function of the metal. (2)
9. The following table shows some measurements of the decay rate of a radionuclide sample. Find the disintegration constant
10. Distinguish between any two types of propagation of Electromagnetic waves with respect to (i) frequency range over which they are applicable (ii) communication systems in which they are used.
Section C :
11. Given a uniformly charged plane/ sheet of surface charge density s = 2X1017 C/m2. (3)
(i) Find the electric field intensity at a point A, 5mm away from the sheet on the left side.
(ii) Given a straight line with three points X, Y & Z placed 50 cm away from the charged sheet on the right side. At which of these points, the field due to the sheet remain the same as that of point A and why?
12. The potential difference across a resistor ‘r’ carrying current ‘I’ is Ir. (3)
(i) Now if the potential difference across ‘r’ is measured using a voltmeter of resistance ‘Rv’, show that the reading of voltmeter is less than the true value.
(ii) Find the percentage error in measuring the potential difference by a voltmeter.
(iii) At what value of Rv, does the voltmeter measures the true potential difference?