ISC 2017 Physics Question Paper for Class 12

About this paper

This is ISC Class 12 Physics Paper 1 (Theory), code 861A, from the 2017 CISCE board examination. It carries 70 marks and runs for three hours plus fifteen minutes of reading time. Part I (20 marks) is a compulsory question with five multiple-choice items and fifteen brief answers. In Part II (50 marks) candidates answer ten five-mark questions: four from Section A on electrostatics, current electricity, magnetism and induction, three from Section B on electromagnetic waves and optics, and three from Section C on modern physics and electronics. Numerical work includes a meter bridge, a voltmeter loading a circuit, a sliding rod in a magnetic field, a compound microscope and the binding energy of neon-20. Log tables may be used and useful constants are printed at the end.

Exam

ISC Class 12

Subject

Physics

Year

2017

Paper code

861A

Maximum marks

70

Time allowed

3 hours + 15 min reading

Questions

15

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 – Section A

  20 marks

  Questions 2–7, five marks each; answer any four

• Part II – Section B

  15 marks

  Questions 8–11, five marks each; answer any three

• Part II – Section C

  15 marks

  Questions 12–15, five marks each; answer any three

Topics covered

• Electric potential and capacitors
• Current electricity, meter bridge and galvanometer
• Earth's magnetism
• Ampère's circuital law and moving charges
• Electromagnetic induction and transformers
• LCR circuits and resonance
• Electromagnetic waves
• Interference, diffraction and polarisation
• Refraction, lenses and optical instruments
• Photoelectric effect and electron diffraction
• Hydrogen spectrum, X-rays and nuclear binding energy
• Semiconductor diodes and logic gates

Questions from this paper

1. Calculate the magnetic flux density at the centre of a circular coil of 50 turns, having a radius of 0.5 m and carrying a current of 5 A.
2. A moving coil galvanometer has a coil of resistance 59 Ω and shows full-scale deflection for a current of 50 mA. How will you convert it into an ammeter with a range of 0 to 3 A?
3. In an ideal transformer, an output of 66 kV is required when an input voltage of 220 V is available. If the primary has 300 turns, how many turns should the secondary have?
4. Find the critical angle for a glass and water pair, given that the refractive index of glass is 1.62 and that of water is 1.33.
5. Starting with an expression for refraction at a single spherical surface, obtain the lens maker's formula.
6. Find the maximum frequency of X-rays produced by an X-ray tube operating at a tube potential of 66 kV.