This page needs to be proofread.
DYNAMICS
155
mirror which is cemented on to the magnet needle. Such instruments are, therefore, called "mirror galvanometers." The light from a lamp is focussed on to the mirror and is from
An image should appear at this position in the text. To use the entire page scan as a placeholder, edit this page and replace "{{missing image}}" with "{{raw image|Electricity (1912) Kapp.djvu/159}}". Otherwise, if you are able to provide the image then please do so. For guidance, see Wikisource:Image guidelines and Help:Adding images. |
there reflected to a semi-transparent scale. On sending a current through the coil the spot of light on the scale is deflected and the amount of its displacement is proportional to the current. By sending a known current