The periodic waves of intensities I₁ and I₂ pass through a region at the same time

⇦

⇨

The periodic waves of intensities I₁ and I₂ pass through a region at the same time in the same direction. The sum of the maximum and minimum intensities is:

Options

(a) I₁ + I₂
(b) (√I₁ + √I₂)²
(c) (√I₁ – √I₂)²
(d) 2 (I₁ + I₂)

Correct Answer:

2 (I₁ + I₂)

Explanation:

The resultant intensity of two periodic waves at a point is given by
I = I₁ + I₂ + 2 √I₁I₂ . cos ?.
Resultant intensity is max. if cos ? = -1
i.e Iₘₐₓ = I₁ + I₂ + 2 √I₁I₂
Resultant intensity is min. if cos ? = +1
i.e, Iₘᵢₙ = I₁ + I₂ – 2 √I₁I₂
Therefore, the sum of the max. and min. intensities is Iₘₐₓ + Iₘᵢₙ
= I₁ + I₂ + 2 √I₁I₂ + I₁ + I₂ – 2 √I₁I₂
= 2 (I₁ + I₂)

Related Questions:

1. A wheel is rotating at 900 rpm about its axis.When the power is cut-off it
2. A ball is projected upwards from the foot of a tower. The ball crosses the top
3. If force(F),length(L) and time(T) be considered fundamental units, then the units of mass
4. Dimensions of resistance in an electrical circuit, in terms of dimension of mass M,
5. If the feedback voltage is increased in a negative feedback amplifier, then

Topics: Ray Optics (94)
Subject: Physics (2479)

---

Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score

18000+ students are using NEETLab to improve their score. What about you?

Solve Previous Year MCQs, Mock Tests, Topicwise Practice Tests, Identify Weak Topics, Formula Flash cards and much more is available in NEETLab Android App to improve your NEET score.

---

Share this page with your friends