The secretion from the abdominal glands of honey bees is ..........

$A$ progressive wave of frequency $50 ~Hz$ is travelling with velocity $350 ~m/s$ through a medium. The change in phase at a given time interval of $0.01 ~s$ is

$A$ particle falls from a height $h$ upon a fixed horizontal plane and rebounds. If $e$ is the coefficient of restitution,the total distance travelled before rebounding has stopped is

The first minima due to a single slit diffraction is at $\theta = 30^o$ for a light of wavelength $5000\,\mathring{A}$. The width of the slit is:

If the foot of the perpendicular from $(0,0,0)$ to a plane is $(1,2,3)$,then the equation of the plane is

$I$. Two non-zero,non-collinear vectors are linearly independent.
$II$. Any three coplanar vectors are linearly dependent.
Which of the above statements is/are true?