Two point charges q₁$$\left( {\sqrt {10} \mu C} \right)$$ and q₂($$-$$ 25 $$\mu $$C) are placed on the x-axis at x = 1 m and x = 4 m respectively. The electric field (in V/m) at a point y = 3 m on y-axis is,
[take $${1 \over {4\pi { \in _0}}}$$ = 9 $$ \times $$ 10⁹ Nm²C^$$-$$2]

A particle having the same charge as of electron moves in a ciurcular path of radius 0.5 cm under the influence of a magnetic field 0f 0.5 T. If an electric field of 100 V/m makes it to move in a straight path, then the mass of the particle is (Given charge of electron = 1.6 $$ \times $$ 10$$-$$¹⁹C)

Expression for time in terms of G(universal gravitional constant), h (Planck constant) and c (speed of light) is proportional to :

The top of a water tank is open to air and its water level is mainted. It is giving out 0.74 m³ water per minute through a circular opening of 2 cm radius in its wall. The depth of the center of the opening from the level of water in the tank is close to :