Two point charges Q each are placed at a distance d apart. A third point charge q is placed at a distance x from mid-point on the perpendicular bisector. The value of x at which charge q will experience the maximum Coulomb's force is :

The speed of light in media 'A' and 'B' are $$2.0 \times {10^{10}}$$ cm/s and $$1.5 \times {10^{10}}$$ cm/s respectively. A ray of light enters from the medium B to A at an incident angle '$$\theta$$'. If the ray suffers total internal reflection, then

The electric field at a point associated with a light wave is given by

E = 200 [sin (6 $$\times$$ 10¹⁵)t + sin (9 $$\times$$ 10¹⁵)t] Vm^$$-$$1

Given : h = 4.14 $$\times$$ 10^$$-$$15 eVs

If this light falls on a metal surface having a work function of 2.50 eV, the maximum kinetic energy of the photoelectrons will be

A capacitor is discharging through a resistor R. Consider in time t₁, the energy stored in the capacitor reduces to half of its initial value and in time t₂, the charge stored reduces to one eighth of its initial value. The ratio t₁/t₂ will be