JEE Advanced 2020 physics questions with solutions

Showing 1–10 of 26 questions

• NumericmediumCurrent electricityCircuit Theory & Kirchhoff’s Laws

  A Wheatstone bridge is initially balanced with R₁ = 60 Ω, R₂ = 100 Ω, R₃ = 300 Ω and R₄ = 500 Ω. The temperature coefficient of R₃ is 0.0004 °C⁻¹. If the temperature of R₃ is increased by 100 °C, find the voltage developed between S and T.

  

  Your answer

  Check answerShow answer

  JEE Advanced 2020

  Open question & full solution →
• NumericeasyWave Motion

  A stationary tuning fork is in resonance with an air column in a pipe. If the tuning fork is moved with a speed of 2 m s⁻¹ in front of the open end of the pipe and parallel to it, the length of the pipe should be changed for the resonance to occur with the moving tuning fork. If the speed of sound in air is 320 m s⁻¹, the smallest value of the percentage change required in the length of the pipe is _________.

  Your answer

  Check answerShow answer

  JEE Advanced 2020

  Open question & full solution →
• MCQmediumElectromagnetic Induction

  A light aluminium disc is horizontal and free to rotate about its axis. A strong magnet is held vertically above the disc away from its axis. If the magnet is revolved about the disc axis, the disc will:

  

  Options

  • Option A

    rotate in the direction opposite to the direction of magnet's motion

  • Option B

    rotate in the same direction as the direction of magnet's motion

  • Option C

    not rotate and its temperature will remain unchanged

  • Option D

    not rotate but its temperature will slowly rise

  Check answerShow answer

  JEE Advanced 2020

  Open question & full solution →
• MCQmediumWave Optics

  A parallel beam of light strikes a piece of transparent glass having cross section as shown in the figure below. Correct shape of the emergent wavefront will be (figures are schematic and not drawn to scale)-

  

  Options

  • Option A

    
  • Option B

    
  • Option C

    
  • Option D

    

  Check answerShow answer

  JEE Advanced 2020

  Open question & full solution →
• MCQmediumElectromagnetic Induction

  A circular coil of radius R and N turns has negligible resistance and hangs vertically. Its ends are connected through a switch to a charged capacitor Q. The coil lies in a horizontal uniform magnetic field B₀ parallel to its plane. When the switch is closed, the capacitor discharges through the coil in a very short time. The angular momentum gained by the coil is:

  

  Options

  • Option A

    (π/2)NQB₀R²

  • Option B

    πNQB₀R²

  • Option C

    2πNQB₀R²

  • Option D

    4πNQB₀R²

  Check answerShow answer

  JEE Advanced 2020

  Open question & full solution →
• Multi-correctdifficultGeometrical opticsrefraction due to curved surface

  A beaker of radius r is filled with water (refractive index 4/3) up to height H and rotates with angular speed ω. The water surface becomes approximately spherical; the height difference between centre and rim is h (h << H, h << r), and the radius of curvature is R. Which statement(s) is/are correct?

  

  Select all that apply

  • Option A

    R = (r² + h²)/(2h)

  • Option B

    R = 3r²/(2h)

  • Option C

    Apparent depth ≈ (3H/2)[1 + Hω²/(2g)]⁻¹

  • Option D

    Apparent depth ≈ (3H/4)[1 + Hω²/(4g)]⁻¹

  Check answerShow answer

  JEE Advanced 2020

  Open question & full solution →
• NumericmediumAC Circuits

  Two LR circuits are magnetically coupled as shown. The self-inductances, resistances, mutual inductance and battery voltages are given in the figure. After both switches are closed simultaneously, find the total work done by the batteries against induced emf until steady state, in mJ.

  

  Your answer

  Check answerShow answer

  JEE Advanced 2020

  Open question & full solution →
• NumericmediumFluid Mechanics

  A hot-air balloon of total mass 480 kg floats at 100 m. Its buoyant volume V is constant. After N sandbags of 1 kg each are dropped it floats at 150 m. Air density varies as ρ(h)=ρ₀ exp(-h/h₀), with ρ₀=1.25 kg m⁻³ and h₀=6000 m. Find N.

  Your answer

  Check answerShow answer

  JEE Advanced 2020

  Open question & full solution →
• Multi-correctmediumElectrostaticElectric field intensity

  A uniform electric field $\vec{E}$= -400√3 $\hat{j}$ N C⁻¹ exists in a region. A positively charged particle is projected with initial speed 2√10 × 10⁶ m s⁻¹ towards target T as shown. Select the correct statement(s) about the projection angle and time of flight.

  

  Select all that apply

  • Option A

    The particle hits T if projected at 45° from the horizontal.

  • Option B

    The particle hits T if projected at 30° or 60° from the horizontal.

  • Option C

    The time to hit T can be $\sqrt{\frac56}$ μs or $\sqrt{\frac52}$ μs.

  • Option D

    The time to hit T is $\sqrt{\frac53}$μs.

  Check answerShow answer

  JEE Advanced 2020

  Open question & full solution →
• MCQdifficultGeometrical opticsapperant depth and shift due to slab

  A large square container with thin transparent vertical walls is filled with water of refractive index 4/3. A vertical wire is held 12 cm from a corner. Looking from that corner, two images of the wire are seen symmetrically about the line of sight. The separation between the images, in cm, is:

  

  Options

  • Option A

    2

  • Option B

    3

  • Option C

    1

  • Option D

    4

  Check answerShow answer

  JEE Advanced 2020

  Open question & full solution →