List of practice Questions

Suppose the charge of a proton and an electron differ slightly. One of them is –e, the other is (e +△e). If the net of electrostatic force and gravitational force between two hydrogen atoms placed at a distance d (much greater than atomic size) apart is zero, then △e is of the order of [Given mass of hydrogen m_h = 1.67 × 10^–27 kg]

The ratio of wavelengths of the last line of Balmer series and the last line of Lyman series is

An arrangement of three parallel straight wires placed perpendicular to plane of paper carrying same current ‘I’ along the same direction is shown in Fig. Magnitude of force per unit length on the middle wire ‘B’ is given by

Two thin dielectric slabs of dielectric constants K₁ and K₂ (K₁ < K₂) are inserted between plates of a parallel plate capacitor, as shown in the figure. The variation of electric field 'E' between the plates with distance 'd' as measured from plate P is correctly shown by: