If I make a wound of a wire [ 32 SWG ] around a rectangular iron core, what will happen to the pointer if current of 3A is passed through the hair springs. Also state the type of scale it describes.

The two most prominent wavelengths in the light emitted by a hydrogen discharge lamp are 656(red) and 486 (blue). light from a hydrogen lamp illuminates a diffraction grating with 500 lines per mm, and the light is observed on a screen 1.50 behind the grating. what is the distance between the first-order red and blue fringes?