physics mcq plz helpppppppppppppppppppppp

[zahraahmed]

 

[akbar arshad]

acc to me da ans wud b D.1400 Hz
is it ryt???

 

[beacon_of_light]

There are 8 waves in 6cm... Then 1 wave will cover 6/8 cm ....

1cm=10ms
6/8cm = 6/8 x (10/1000) = 7.5 x 10^-3 seconds.
Frequency = 1/T = 1/ (7.5 x 10^-3) = 133 Hz which is approximately equal to 140 Hz

 

[usman]

There are 8 waves in 6cm... Then 1 wave will cover 6/8 cm ....

1cm=10ms
6/8cm = 6/8 x (10/1000) = 7.5 x 10^-3 seconds.
Frequency = 1/T = 1/ (7.5 x 10^-3) = 133 Hz which is approximately equal to 140 Hz

dat's ri8