If $\theta$ lies in the first quadrant and $5 \tan \theta = 4$,then $\frac{5 \sin \theta - 3 \cos \theta}{\sin \theta + 2 \cos \theta}$ is equal to

Which of the following statements are true about acceleration due to gravity?
$(a)$ $g$ decreases in moving away from the centre if $r > R$
$(b)$ $g$ decreases in moving away from the centre if $r < R$
$(c)$ $g$ is zero at the centre of the Earth
$(d)$ $g$ decreases if the Earth stops rotating on its axis

The diameter of the objective lens of a telescope is $250 \ cm$. For light of wavelength $600 \ nm$ coming from a distant object,the limit of resolution of the telescope is close to:

$A$ closed hollow insulated cylinder is filled with gas at $0^oC$ and also contains an insulated piston of negligible weight and negligible thickness at the middle point. The gas on one side of the piston is heated to $100^oC$. If the piston moves $5\,cm$,the length of the hollow cylinder is ..... $cm$.

$\sqrt[4]{17 + 12\sqrt{2}} = $

When a piece of bread is chewed,it tastes sweet because: