Continuous spectrum is produced by(multiple correct):A. Incandescent electric bulbB. SunC. Hydrogen moleculesD. Sodium vapour lamp

The correct answers are: A) Incandescent electric bulb and B) Sun
A continuous spectrum contains all wavelengths of light within a certain range, with no gaps or missing wavelengths. It is produced by sources that emit light over a wide range of energies (or frequencies).
1. Incandescent Electric Bulb (A): An incandescent bulb produces a continuous spectrum because the filament inside the bulb is heated to a high temperature, causing it to emit light across a wide range of wavelengths. The emitted light spans the entire visible spectrum and extends into the infrared region, producing a continuous spectrum.
2. Sun (B): The Sun also emits a continuous spectrum. It is essentially a black-body radiator, meaning it emits light across a broad spectrum of wavelengths. The light from the Sun includes not only visible light but also ultraviolet and infrared radiation, forming a continuous spectrum.
3. Hydrogen Molecules (C): Hydrogen molecules, specifically in a gas phase, do not produce a continuous spectrum. Instead, they produce a line spectrum due to the discrete energy levels in hydrogen atoms. When electrons transition between energy levels, they emit light at specific wavelengths, resulting in a set of discrete lines in the spectrum (known as the hydrogen spectral series).
4. Sodium Vapor Lamp (D): A sodium vapor lamp does not produce a continuous spectrum. Instead, it emits light at specific wavelengths, resulting in a line spectrum. The characteristic bright yellow lines of sodium vapor are due to the excitation of sodium atoms, and the light emitted corresponds to specific transitions between energy levels in sodium atoms.
Conclusion:
A continuous spectrum is produced by sources like the incandescent electric bulb and the Sun because they emit light across a wide range of wavelengths. The hydrogen molecules and sodium vapor lamp produce line spectra, not continuous spectra.