I applied logic and got the answer wrong?
The question asked, what is time period?
I knew what frequency was. Freq=1/timeperiod which is 1000 , therefore my answer was timeperiod = 1x 1000 which is 1000 m/s.
The teacher's answer was time period 1/1000.
But, For example speed = distance/ time, to find distance= speed x time. shouldn't this concept apply to frequency as well.