In a double-slit interference experiment with slit separation d and light wavelength lambda, what is the path difference for the third dark fringe?
Answer and explanation
Correct answer: B. 2.5 * lambda
- Step 1: Destructive interference occurs when the path difference satisfies delta x = (m + 0.5) lambda. Step 2. For the first dark fringe m = 0 (0.5lambda); second m = 1 (1.5lambda); third m = 2 (2.5lambda). *Answer: 2.5 lambda. Why not the others:* Integer multiples mlambda yield constructive bright fringes.
Practise more Rotational Dynamics, Simple Harmonic Motion, Gravity and Wave Interference.
Free questions with an explanation for every one, and full timed New Zealand Scholarship mock tests.
More Rotational Dynamics, Simple Harmonic Motion, Gravity and Wave Interference questions
- A figure skater spins with angular velocity omega_1 with arms outstretched. When she draws her arms inwards, her moment of inertia decreases…
- A mass-spring system executes simple harmonic motion with amplitude A. At what displacement x from equilibrium is the kinetic energy equal t…
- What is the orbital speed of a satellite in circular orbit around Earth at radius r, where M is Earth's mass?
- A uniform rod of length L and mass M is hinged at one end and released from horizontal rest. What is its initial angular acceleration (I = (…
- What is the period of a simple pendulum of length l in a region of gravitational acceleration g?
- A solid cylinder (I = 0.5MR^2) rolls down an incline of height h without slipping. What is its linear speed at the bottom?