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Physics — Stream SX/SB

Electrodynamics, modern physics, waves, and thermodynamics for Class 12 / 1st-year college

Key Concepts
  • Electrostatics and current electricity
  • Magnetism and electromagnetic induction
  • Ray and wave optics
  • Modern physics: photoelectric effect and atomic models
Important Formulae
Coulomb's law F = kq₁q₂/r²
Mirror / lens formula 1/f = 1/v − 1/u
Photon energy E = hf = hc/λ
Bohr energy levels E_n = −13.6/n² eV
Quick Tips
  • Master sign conventions in optics before attempting numericals.
  • Many SX questions blend two topics — read carefully for the link.
Sample Practice Questions

  1. The speed of light in vacuum is approximately:

    • 3×10⁶ m/s
    • 3×10⁸ m/s
    • 3×10¹⁰ m/s
    • 1.5×10⁸ m/s
    Show answer

    Answer: 3×10⁸ m/s

  2. The photoelectric effect demonstrates the:

    • Wave nature of light
    • Particle nature of light
    • Magnetic nature of light
    • Thermal nature of light
    Show answer

    Answer: Particle nature of light

  3. The SI unit of electrical resistance is the:

    • volt
    • ampere
    • ohm
    • watt
    Show answer

    Answer: ohm

  4. The lens (and mirror) formula is:

    • 1/f = 1/v + 1/u
    • 1/f = 1/v − 1/u
    • f = v + u
    • 1/f = u − v
    Show answer

    Answer: 1/f = 1/v − 1/u

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Practice Questions

Practise KVPY questions on Physics — Stream SX/SB. Answers are revealed after each question.

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Physics