MCQ Detailed View

Spray bottles, such as perfume sprays, household cleaners, or window sprays, work on the concept of Bernoulli’s Principle from fluid dynamics. According to this principle, an increase in the speed of a fluid (air, in this case) results in a decrease in pressure. This pressure difference is what allows liquid to rise and be dispersed as a fine mist.

Here’s how it works step by step:

1. 
   

   When you press the spray nozzle, air is forced through a narrow passage.

   
   


2. 
   

   This creates a region of low pressure above the liquid inside the bottle.

   
   


3. 
   

   Due to the pressure difference, the liquid rises up through a tube from the container.

   
   


4. 
   

   The liquid is then broken into tiny droplets by the fast-moving air, forming a mist or spray.

   
   

This same principle is applied in carburetors, insect sprays, and paint sprays. All these devices use the velocity-pressure relationship to draw liquid into an airstream.

Looking at the answer choices:

• 
  

  Capillary action explains liquid movement in thin tubes (like in plants), but not sprays.

  
  


• 
  

  Bernoulli’s Principle is correct since it explains suction and atomization in spray bottles.

  
  


• 
  

  Pascal’s Law deals with pressure transmission in fluids, used in hydraulics, not sprays.

  
  


• 
  

  Stoke’s Law relates to viscosity and motion of particles in fluids, not relevant here.

  
  

This example demonstrates the importance of Bernoulli’s Principle in daily life. From airplanes flying to atomizers and sprays, this principle is widely used in science and technology.

In conclusion, perfume sprays and household spray bottles work on Bernoulli’s Principle, where fast-moving air reduces pressure and draws liquid upward to create a fine mist.