In the production of X-rays by a Coolidge tube, the changes which can be made in its operation are listed in column I. The possible effects of such changes are listed in column-II COLUMN-I                                                                          COLUMN-IIA) Change in the current flowing through           P) Harder or softer X-rays areThe filament (emitter of cathode)                             produced B) Change in the potential difference applied    Q) wavelengths of the      Across the tube                                                          characteristic X-rays change  C) Change in the metal used as the target           R) Intensity of the X-rays                                                                                          change D) Rotating the tube from a horizontal                  S) cut of wavelengths          position to a vertical position                               changes