question_answer

The following equations represent progressive transverse waves \[{{Z}_{1}}=A\cos (\omega \,t-kx)\], \[{{Z}_{2}}=A\cos (\omega \,t+kx)\], \[{{Z}_{3}}=A\cos (\omega \,t+ky)\] and \[{{Z}_{4}}=A\cos (2\omega \,t-2ky)\]. A stationary wave will be formed by superposing [MP PET 1993]

A)            \[{{Z}_{1}}\] and \[{{Z}_{2}}\]                                           

B)            \[{{Z}_{1}}\] and \[{{Z}_{4}}\]

C)            \[{{Z}_{2}}\] and \[{{Z}_{3}}\]                                           

D)            \[{{Z}_{3}}\] and \[{{Z}_{4}}\]