Question

An incandescent filament emits a spectrum which is:
A) Line spectrum
B) Band spectrum
C) Continuous spectrum
D) Characterizes spectrum

Answer 1

Hint : The filament is observed to break at random locations after a sufficiently long time of operation due to non-uniform evaporation of tungsten; it means that temperature distribution in the filament is not uniform. As filament starts melting the filament get thinner or the cross section area of the filament decreases

Complete step-by-step solution:
A continuous spectrum which usually means a set of attainable values for some quantity that is best described as an interval of real numbers, as opposed to discrete spectrum and a set of attainable values that is discrete in a mathematical sense.
Some examples of a continuous spectrum from which the name is derived is the part of the spectrum of the light emitted by excited atoms of hydrogen that is because of free electrons becoming bound to a hydrogen ion and emitting photons, which are smoothly spread over a wide range of wavelengths.
An incandescent bulb, a candle or a red hot iron piece emits light, which has continuously varying wavelengths because of which it shows continuous emission spectrum
So the correct option is C.

Note: In the electromagnetic spectrum the electromagnetic waves are arranged according to their frequencies and also with respect to their wavelength. The frequency ranges in the electromagnetic spectrum are divided into different bands and these bands are called by different names. Electromagnetic waves are formed when an electric field comes in contact with a magnetic field and also electromagnetic waves are the synchronized oscillations of magnetic and electric fields.