Previous Year Question with Solution 2024 Physics Class 12 Board Exam CHSE Odisha
PHYSICS (SCIENCE) – 2024 (A)
Code: 603 R/E (Regular / Ex-Regular)
Full Marks: 70
Time: 3 hours
The figures in the right-hand margin indicate marks.
Answer all questions from Groups A and B serially and continuously, and any three questions from Group C.
No electronic gadgets are allowed into the Examination Hall.
Symbols used in the questions carry their usual meanings.
GROUP – A
1. Multiple choice questions (Answer all)
Choose the correct answer out of the four alternatives given at the end of each bit:
1×7=7
(a) The graph between maximum kinetic energy K of photoelectrons and frequency ν\nuν of the incident radiation in photoelectric effect is
(i) straight line passing through the origin
(ii) straight line not passing through the origin
(iii) ellipse
(iv) circle
(b) The nature of nuclear force is
(i) electric charge dependent
(ii) spin-dependent
(iii) long range
(iv) unsaturated
(c) The angle between an equipotential surface and the electric line of force at a point is
(i) 0∘
(ii) 45∘
(iii) 90∘
(iv) 180∘
(d) The ratio between resultant capacitances Cs and Cp of two equal capacitors in series combination and parallel combination respectively is
(i) 1:1
(ii) 2:1
(iii) 4:1
(iv) 8:1
(e) The SI unit of self-inductance of a coil is
(i) farad
(ii) henry
(iii) weber
(iv) oersted
(f) For a series L–C–R circuit at resonance, the relation among inductance L, capacitance C and angular frequency ω is
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(g) The SI unit of power of a lens is
(i) dioptre
(ii) newton
(iii) huygens
(iv) lumen
2. Very short answer questions (Answer all)
Answer each bit as directed:
1×7=7
(a) The electronic energy levels for different orbits in hydrogen atom are equispaced. (State ‘True’ or ‘False’.)
(b) For a convex lens, at which position should an object be placed so as to have a real and magnified image?
(c) Write the dimensional formula of magnetic permeability μ.
(d) Draw the circuit symbol of a NOR gate.
(e) Which nucleus has maximum average binding energy per nucleon?
(f) Write the de Broglie relation for matter waves.
(g) What happens to the electrical resistance of a semiconductor when its temperature is raised?
GROUP – B
3. Short answer questions (Answer any seven)
2×7=14
(a) Write the circuit symbol and truth table for an OR gate.
(b) Calculate the refractive index of a medium for which the critical angle is 30∘
(c) Define “half-life” and “average life” of a radioactive substance.
(d) Can two magnetic lines of force intersect each other? Explain why.
(e) State any two characteristics of electromagnetic waves.
(f) Draw the circuit symbol and state the truth table for a NAND gate.
(g) Four resistors are connected as shown below. Find the resultant resistance between points A and B.
A — 2 Ω — C — 1 Ω — B
\
3 Ω
\
D — 6 Ω — B
(h) Distinguish between paramagnetic and diamagnetic substances.
(i) Define “mass defect” and “binding energy” of a nucleus.
(j) Find the resultant capacitance between points A and B for the following combination of capacitors:
A — 2 F — 4 F — 2 F — B
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1 F
|
B
4. Short derivations / explanations (Answer any seven)
3×7=21
(a) Derive an expression for the self-inductance of a circular coil of NNN turns.
(b) Establish the relation between focal length and radius of curvature of a concave mirror.
(c) State the conditions for sustained interference of light waves from two sources. Write the conditions for intensity maxima and minima.
(d) Charges +1 μC, +3 , −5 μC are placed at the corners of an equilateral triangle with side 10 sqrt 3 cm. Calculate the electrostatic potential at the centre of the triangle.
(e) State and explain the characteristics of nuclear force.
(f) Derive an expression for the energy stored in a capacitor of capacitance C, when it is charged with charge Q.
(g) Describe the magnetic elements of the earth.
(h) In photoelectric effect, explain graphically how photocurrent varies with (i) intensity and (ii) frequency of the incident radiation.
(i) Find the RMS value of the AC current I=Io sin ωt.
(j) What is depletion layer in a P–N junction diode?
GROUP – C
5–9. Long answer questions (Answer any three)
7×3=21
State Bohr’s postulates for hydrogen atom. Using these, derive expressions for
the radius of allowed orbits, and
the total energy of the electron in those orbits.
With a neat circuit diagram, explain the principle and working of a full-wave rectifier using two P–N junction diodes.
Describe Young’s double-slit experiment for the interference of light and derive the expression for fringe width.
8- What is an electric dipole? Derive expressions for the electric field due to a dipole at a point in
(a) end-on (axial) position, and
(b) broad-side-on (equatorial) position.
9-State Biot–Savart law. Use it to derive an expression for the magnetic field due to an infinitely long straight current-carrying conductor at a distance r from it.
Answer Sheet
