A wave travelling along the x-axis is described by the equation y = 0.005 cos (αx - βt). If the wavelength and the time period of the wave are 0.08 m and 2 seconds respectively. Find the values of α and β.

  1. α = 25π and β = π
  2. α = 0.08/π and β = 2/π
  3. α = 0.04/π and β = 1/π
  4. α = 12.5π and β = π/2

Answer (Detailed Solution Below)

Option 1 : α = 25π and β = π
Free
All India Agniveer Army GD: Ultimate Live Test - 04
29.8 K Users
50 Questions 100 Marks 60 Mins

Detailed Solution

Download Solution PDF

CONCEPT:

The general equation of wave motion is given by:

y =  Asin (kx - ωt)

where A = amplitude, ω = angular frequency, k = angular wavenumber, t = time, and x is position

  • Wavelength (λ): Distance between two nearest particles vibrating in the same phase.
  • Frequency (f): Number of vibrations complete by a particle in one second.
  • Time Period (T): Time taken by the wave to travel a distance equal to one wavelength.
  • Amplitude (A): Maximum displacement of vibrating particles from the mean position.

The relationship between frequency (f), wavelength (λ), and velocity (v) of a wave is given by:

f × λ = v 

CALCULATION:

Given that:

y = 0.005 cos (αx - βt)

λ = 0.08 m, and Time period (T) = 2 sec

By comparing the given equation with the general equation we get:

α = k and β = ω 

We know that ω = 2π/T and k = 2π/λ

α = 2π/λ

β = 2π/T

α = 2π/0.08

α = 25π

β = 2π/2

β = π 

Hence option 1 is correct

Latest Indian Coast Guard Navik GD Updates

Last updated on Jul 4, 2025

-> The Indian Coast Guard Navik GD Application Correction Window is open now. Candidates can make the changes in the Application Forms through the link provided on the official website of the Indian Navy.

-> A total of 260 vacancies have been released through the Coast Guard Enrolled Personnel Test (CGEPT) for the 01/2026 and 02/2026 batch.

-> Candidates can apply online from 11th to 25th June 2025.

-> Candidates who have completed their 10+2 with Maths and Physics are eligible for this post. 

-> Candidates must go through the Indian Coast Guard Navik GD previous year papers.

More The Wave Equation Questions

Get Free Access Now
Hot Links: teen patti boss teen patti master online teen patti win