19.
Which one of the following is not the component of the spectrometer?
i) Telescope
ii) Collimator
iii) Prism table
iv) Mercury lamp
Answers
collimator...........
The component which is NOT present in the spectrometer is the Mercury lamp.
So, (iv) Mercury lamp is the correction option.
Explanation
The spectrometer consists of a graduated circle, generally fixed in a horizontal position, to which is attached a collimator and a telescope.
The movable arm carries an astronomical telescope which is always directed towards the centre of the graduated circle. The position of the telescope with reference to the fixed circle may be read by means of a vernier.
The collimator focuses a beam of light and aligns it in a different direction, making it parallel or collimated
The prism table is used for mounting the prism, grating etc.
Mercury lamps are also used but they are used as a light source and cannot be called a component of the spectrometer.