JAC Class 12 Physics Question Paper 2012 with Solution

About this paper

This is the Jharkhand Academic Council (JAC) Class 12 Physics paper from the 2012 board examination, with an answer written under every question. Instructions and most questions are printed in both English and Hindi. There are 30 questions: eight one-mark multiple-choice questions, ten two-mark questions, nine three-mark questions and three five-mark questions, adding up to 70 marks. Each five-mark question has an alternative. The long answers cover the Wheatstone bridge, the cyclotron and the compound microscope, with the torque on a magnetic dipole and the mirror formula for a convex mirror as the alternatives.

Exam

JAC Class 12

Subject

Physics

Year

2012

Maximum marks

70

Questions

30

Pages

5

Answers included

Yes

Paper pattern

• Questions 1–8

  8 marks

  Objective multiple-choice questions, one mark each

• Questions 9–18

  20 marks

  Short answer questions, two marks each

• Questions 19–27

  27 marks

  Short answer questions, three marks each

• Questions 28–30

  15 marks

  Long answer questions, five marks each, each with an alternative

Topics covered

• Electric charge and Gauss's law
• Current electricity and Wheatstone bridge
• Moving charges and the cyclotron
• Earth's magnetism and magnetic dipoles
• Electromagnetic induction and Lenz's law
• Alternating current and LCR circuits
• Electromagnetic waves
• Ray optics and optical instruments
• Interference of light
• Photoelectric effect
• Nuclei and radioactivity
• Semiconductors, logic gates and communication systems

Questions from this paper

1. State and explain the principle of quantization of charge.
2. Calculate the frequency of a photon with energy 7.5 eV (h = 6.62 × 10⁻³⁴ J s).
3. Why are sky waves not used for transmitting TV signals?
4. A circuit containing an 80 mH inductor, a 60 µF capacitor and a 15 Ω resistor is connected to a 230 V, 50 Hz supply. Obtain the average power transferred to each element of the circuit and the total power absorbed.
5. A convex lens of focal length 40 cm is placed in contact with a concave lens of focal length 20 cm. What is the equivalent focal length of the combination?
6. Explain with the help of a labelled diagram the principle, construction and working of a cyclotron. Show that the cyclotron frequency does not depend on the speed of the particle.