Electric Charges and Fields — Physics STD 12 Science — Question

Which conservation law is obeyed in Einstein's photoelectric equation?

A metallic loop is placed in a magnetic field. If a current is passed through it, then(a) The ring will feel a force of attraction(b) The ring will feel a force of repulsion(c) It will move to and fro about its centre of gravity(d) None of these

A thin slice is cut out of a glass cylinder along a plane parallel to its axis. The slice is placed on a flat glass plae as shown in figure. The observed interference fringes from this combination shall be:

The magnetic dipole moment of a current carrying coil does not depend upon:

The coil is wound on an iron core and looped back on itself so that core has two sets of closely wound coils carrying current in opposite directions. The self inductance is.

The value of electric permittivity of free space is:

The band spectra (characteristic of molecular species) is due to emission of radiation:

50% of the X-ray coming from a Coolidge tube is able to pass through a 0.1mm thick aluminium foil. The potential difference between the target and the filament is increased. The thickness of the aluminium foil that will allow 50% of the X-ray to pass through will be:

A parallel plate condenser is connected with the terminals of a battery. The distance between the plates is 6mm. If a glass plate (dielectric constant K  = 9) of 4.5 mm  is introduced between them, then the capacity will become(a) 2 times(b) The same(c) 3 times(d) 4 times

The phenomenon utilised in an optical fibre is(a) Refraction(b) Interference(c) Polarization(d) Total internal reflection