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.

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 ?

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

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 ?