Name the electromagnetic radiations used for (a) water purification, and (b) eye surgery.

A proton and an electron travelling along parallel paths enter a region of uniform magnetic field, acting perpendicular to their paths. Which of them will move in a circular path with higher frequency ?

Draw graphs showing variation of photoelectric current with applied voltage for two incident radiations of equal frequency and different intensities. Mark the graph for the radiation of higher intensity.

Four nuclei of an element undergo fusion to form a heavier nucleus, with release of energy. Which of the two- the parent or the daughter nucleus - would have higher binding energy per nucleon ?

Which mode of propagation is used by short wave broadcast services ?