ISC 2014 Physics Question Paper for Class 12

About this paper

This is ISC Class 12 Physics Paper 1 (Theory), code 861A, from the 2014 CISCE board examination. It runs for three hours plus fifteen minutes of reading time and is split into Part I (20 marks) and Part II (50 marks). Part I is one compulsory question: five multiple-choice items followed by fifteen short questions to be answered briefly. In Part II candidates answer six questions, two from each of Sections A, B and C, which cover electricity and magnetism, optics, and modern physics respectively. Several questions rely on printed figures, such as a Wheatstone-type circuit, a prism immersed in liquid and an atomic energy-level diagram. Log tables may be used and a list of physical constants is printed at the end.

Exam

ISC Class 12

Subject

Physics

Year

2014

Paper code

861A

Maximum marks

70

Time allowed

3 hours + 15 min reading

Questions

10

Pages

8

Answers included

No, questions only

Paper pattern

• Part I

  20 marks

  Question 1, compulsory: 5 multiple-choice items and 15 short answers

• Part II

  50 marks

  Six questions to be answered, two from each of Section A (Questions 2–4, electricity and magnetism), Section B (Questions 5–7, optics and electromagnetic waves) and Section C (Questions 8–10, modern physics and electronics)

Topics covered

• Electrostatics and capacitors
• Current electricity and potentiometer
• Thermoelectricity
• Magnetic effects of current and magnetic materials
• Alternating current
• Electromagnetic spectrum
• Interference and polarisation
• Prisms, lenses and optical instruments
• Photoelectric effect and matter waves
• Atomic energy levels and X-rays
• Nuclear energy and reactors
• Semiconductors and logic gates

Questions from this paper

1. The half-life of a certain radioactive element is 3.465 days. Find its disintegration constant.
2. Find the magnetic flux density at a point on the axis of a long solenoid having 5000 turns/m when it is carrying a current of 2 A.
3. An alternating emf of 110 V is applied to a circuit containing a resistance of 80 Ω and an inductor in series, and the current lags the supply voltage by tan⁻¹(3/4). Find the inductive reactance, the impedance and the current in the circuit.
4. An astronomical telescope uses two lenses of powers 10 dioptre and 1 dioptre. If the final image of a distant object is formed at infinity, calculate the length of the telescope.
5. The voltage applied between the cathode and anode of an X-ray tube is 18 kV. Calculate the minimum wavelength of the X-rays produced.
6. With the help of a diagram, show how you can use several NAND gates to obtain an OR gate.