If the chord $y=mx+1$ of the circle $x^2+y^2=1$ subtends an angle of $45^{\circ}$ at the major segment of the circle,then the value of $m$ is:

$A$ and $B$ are two metallic rings placed at opposite sides of an infinitely long straight conducting wire as shown. If the current in the wire is slowly decreased,the direction of the induced current will be:

Despite being multicellular,its cells are not organized into tissues.

What do pesticides include?

Which one of the following is a stimulant?

The packing efficiency of the two-dimensional square unit cell shown below is ........... $\%$