A tuning fork produce 2 beats when sounded with one oscillator of frequency 514 Hz, and produces 6 beats with the other oscillator of frequency 510 Hz. The frequency of tuning fork is
516 Hz
510 Hz
514 Hz
520 Hz
If a liquid does not wet a solid surface, then its angle ofcontact is
acute angle
obtuse angle
right angle
None of these
To hear the echo in 1 s, the minimum distance of the source from the reflecting surface should be
28 m
18 m
19 m
165 m
If length of a simple pendulum increases by 300%, then its time period increases by
100 %
200 %
300 %
400 %
When a force F is applied on a wire oflength L and radius r, extension produce is l. If same force F is applied on the same material wire of length 2 L and radius 2r, then extension will be
l
2l
l/2
4l
Intensity of a source of a 100 cd at a distance 2 m is
25 lux
50 lux
75 lux
150 lux
A.
25 lux
If tension of sonometer wire is made four times, then its frequency will change by a factor of
2
4
1/2
6