UPPSC 2020 GS-I General science
Question

Which of the following is used in fire alarm ?

Answer & Solution

Answer: (Detailed Solution Below)

Option A: Photo cell

Detailed Solution:

The correct answer is “Photo cell”.

Photo cell is used in fire alarms. It detects smoke by measuring changes in light intensity. When smoke particles enter the chamber, they scatter the light, causing a decrease in light reaching the photocell. This change triggers the alarm.

Similar Questions:

Which of the following statements is not correct?
  1. Air conditioners and air coolers both regulate the temperature
  2. Air conditioners and air coolers both regulate the humidity
  3. Air condition control humidity but air cooler does not control humidity
  4. Both controls the speed of air
Which one of the following is not correctly matched?
  1. Decibel–unit of loudness of sound
  2. Horse power–unit of power
  3. Nautical mile–unit of distance in navigation
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Botulism is:
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  2. Food-borne intoxication
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  2. Brittle Star
  3. Black Hole
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  3. Zinc and Lead
  4. Zinc and Copper
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  1. Lord Hastings
  2. Lord William Bentinck
  3. Lord Dalhousie
  4. Lord Auckland
Change in the base sequence within a gene is called:
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Reason (R): Oxides of carbon are emitted when coal burns.

Select the correct answer using the code given below:
Code:
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