Q145 / 200 · JIPMER 2008 · Physics

Flash light equipped with a new set of batteries, produces bright white light. As the batteries wear out

  • A
    the light intensity gets reduced with no change in its colour
  • B
    light colour changes first to yellow and then red with no change in intensity
  • C
    it stops working suddenly while giving white light
  • Correct answer
    D
    colour changes to red and also intensity gets reduced

Solution

As batteries wear out, temperature of filament of flash light attains lesser value, therefore intensity of radiation reduces. Also dominating wavelength $\left(\lambda_m\right)$ in spectrum, which is the red colour, increases.

Hence, the correct answer is option: 'D'.

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