The equation of a straight line,perpendicular to $3x - 4y = 6$ and forming a triangle of area $6$ sq. units with the coordinate axes,is

The length of a magnet is large compared to its width and breadth. The time period of its oscillation in a vibration magnetometer is $2 ~s$. The magnet is cut along its length into three equal parts and three parts are then placed on each other with their like poles together. The time period of this combination will be

Consider the following statements $A$ and $B$ and identify the correct answer given below:
$(A)$ $A$ body initially at rest is acted upon by a constant force. The rate of change of its kinetic energy varies linearly with time.
$(B)$ When a body is at rest,it must be in equilibrium.

Silica is added to roasted copper ore during extraction in order to remove

Mass of living matter at a trophic level in an area at any time is called

Anhydrous $Na_2CO_3$ is also known as