JAC Class 12 Physics Question Paper 2018 with Solution

About this paper

This is the Jharkhand Academic Council (JAC) Class 12 Physics paper from the 2018 board examination, with an answer under each question. It has 20 questions in four groups: 15 objective parts, eight short questions, eight longer questions and three long answers. The short set includes an equipotential surface, a 10 V battery of internal resistance 3 Ω supplying 0.5 A, magnetic declination and dip, the de Broglie wavelength of a proton, and an LED. Later questions compare the emfs of two cells, find the current through a 60 μF capacitor on a 110 V, 60 Hz supply, and correct a myopic eye whose far point is 70 cm. The galvanometer question has Ampere's law for a toroid as its alternative. Marks and time are not printed.

Exam

JAC Class 12

Subject

Physics

Year

2018

Questions

20

Pages

8

Answers included

Yes

Paper pattern

• Group A

  Question 1 with 15 objective parts

• Group B

  Questions 2–9

• Group C

  Questions 10–17

• Group D

  Questions 18–20; the galvanometer question has Ampere's law as an alternative, and the lens question has Young's experiment

Topics covered

• Electrostatics, equipotential surfaces and Gauss's theorem
• Current electricity and internal resistance
• Earth's magnetism
• Electromagnetic induction and self-inductance
• Alternating current and capacitive reactance
• Electromagnetic waves
• Ray optics, lenses and total internal reflection
• Defects of vision
• de Broglie waves
• Bohr's model and nuclear binding energy
• Semiconductors, LEDs and transistor amplifiers
• Modulation

Questions from this paper

1. Define an equipotential surface and mention two of its properties.
2. A battery of emf 10 V and internal resistance 3 Ω is connected to a resistor. If the current is 0.5 A, what is the resistance of the resistor?
3. A 60 μF capacitor is connected to a 110 V, 60 Hz a.c. supply. Determine the rms current in the circuit.
4. The far point of a myopic person is 70 cm in front of the eye. Calculate the focal length and power of the lens needed to see distant objects clearly.
5. Mention the postulates of Bohr's model of the atom. What are its limitations?
6. Describe, with principle, construction and working, a moving-coil galvanometer.