If a copper rod carries a direct current,the magnetic field associated with the current will be

Leaves that produce microspores and megaspores are called:

You are given a fairly old piece of dicot stem and a dicot root. Which of the following anatomical structures will you use to distinguish between the two?

If $a \sin^2 \theta + b \cos^2 \theta = c$,then $\tan^2 \theta$ is equal to

$A$ water barrel having water up to a depth $d$ is placed on a table of height $h$. $A$ small hole is made on the wall of the barrel at its bottom. If the stream of water coming out of the hole falls on the ground at a horizontal distance $R$ from the barrel,then the value of $d$ is

If $P=(0,1,0)$ and $Q=(0,0,1)$, then the length of the projection of the line segment $PQ$ on the plane $x+y+z=3$ is