An equation ` y = a cos ^( 2 ) (2 pi nt - (2pi x ) / ( lamda ) ) ` represents a wave with : -

Options

A. amplitude a, frequency n and wavelength ` lamda `
B. amplitude a, frequency 2n and wavelength 2`lamda `
C. amplitude ` (a ) /( 2 ) ` , frequency 2n and wavelength `lamda`
D. amplitude ` ( a ) / ( 2 ) `, frequency 2n and wavelength ` ( lamda ) / ( 2 ) `

Answer

D

Explanation

` y = a cos ^ 2 ( 2 pi nt - ( 2pi x ) /( lamda ) ) `
` = ( a ) /( 2 ) [ 1 + cos 2 ( 2pi nt - ( 2pi ) / ( lamda ) x ) ] `
` rArr y = ( a ) /( 2 ) [ 1 + cos 2pi { 2 nt - ( x ) / ( lamda //2 ) }] `