A table fan, rotating at a speed of 2400 rpm, is switched off and the resulting variation of the rpm with time is shown in the figure. The total number of revolutions of the fan before it comes to rest is

A table fan, rotating at a speed of 2400 rpm, is switched off and the

1.	A table fan, rotating at a speed of 2400 rpm, is switched off and the resulting variation of the rpm with time is shown in the figure. The total number of revolutions of the fan before it comes to rest is
Answer» 420 190 280 380 Solution :Area under `n-t` GRAPH will give total number of REVOLUTION before coming to stop Area = Total number of REVOLUTIONS `=(1)/(2)xx8xx((1800)/(60))+8xx(600)/(60)+(1)/(2)xx16xx((600)/(60))` `=120+80+80` `=280`.