A progressive wave `y=1 mm sin(2pi x - ((pi t)/100)` is moving along positive x-axis. x is in m and t in sec. List-I gives position x and time t. List-II comments on slope of string and position of particle at that point.
`{:("List I",,"List II"),("P. x=0, t=5 sec",,"1. slope is zero"),("Q. x=1/2 m, t=5 sec",,"2. Particle is at mean position"),("R. x=3/2 m, t=50 sec",,"3. slope is -ve"),("S. x= 3/2 m, t=100 sec",,"4. Displacement y of particle is negative"):}`

Options

A. P-4,Q-1,R-2,S-3
B. P-3,Q-4,R-1,S-2
C. P-4,Q-3,R-1,S-2
D. P-2,Q-1,R-4,S-3

Answer

C

Explanation

`(dely)/(delx)=2picos`
`(P) (dely)/(delx)=2pi cos (pi)/20 , y=-ve`
`(q) (dely)/(delx)=2p cos(pi-(pi)/20) =-ve`
`y=+sin(pi-(pi)/20)=+ve`