If the resultant of all external forces acting on a system of particles is zero, then from an inertial frame one can surely say that
The reverse current in the semiconductor diode changes from $$20 \mu \mathrm{A}$$ to $$40 \mu \mathrm{A}$$ when the reverse potential is changed from $$10 \mathrm{~V}$$ to $$15 \mathrm{~V}$$, then the reverse resistance of the junction diode will be :
A drone is flying due west, a little above the train, with a speed of $$10 \mathrm{~m} / \mathrm{s}$$. A 270 meter long train is moving due east at a speed of $$20 \mathrm{~m} / \mathrm{s}$$. The time taken by the drone to cross the train is
$$\mathrm{F}_{\mathrm{A}}, \mathrm{F}_{\mathrm{B}}$$ and $$\mathrm{F}_{\mathrm{C}}$$ are three forces acting at point $$\mathrm{P}$$ as shown in figure. The whole system is in equilibrium state. The magnitude of $$\mathrm{F}_{\mathrm{A}}$$ is