A long cylindrical vessel is half filled with a liquid. When the vessel is rotated about its own vertical axis, the liquid rises up near the wall. If the radius of vessel is 5 cm and its rotational speed is 2 rotations per second, then the difference in the heights between the centre and the sides, in cm, will be :

The charge on a capacitor plate in a circuit, as a function of time, is shown in the figure :


When is the value of current at t = 4 s ?

Two particles A, B are moving on two concentric circles of radii R₁ and R₂ with equal angular speed $$\omega $$. At t = 0, their positions and direction of motion are shown in the figure. :



The relative velocity $${\overrightarrow V _A} - {\overrightarrow V _B}$$ at t = $${\pi \over {2\omega }}$$ is given by :

The mean intensity of radiation on the surface of the Sun is about 10⁸ W/m² . The rms value of the corresponding magnetic field is closet to :