MEDIUM
9th CBSE
IMPORTANT
Earn 100

What is Brownian motion? Draw a diagram to show the movement of a particle (like a pollen grain) during Brownian motion.

Important Questions on Model Test Paper 3

MEDIUM
9th CBSE
IMPORTANT
Science for Ninth Class (Part-3) Biology>Chapter 9 - Model Test Paper 3>SECTION-A>Q 16
In a beam of sunlight entering a room, we can sometimes see dust particles moving in a haphazard way in the air. Why do these dust particles move? 
HARD
9th CBSE
IMPORTANT
Science for Ninth Class (Part-3) Biology>Chapter 9 - Model Test Paper 3>SECTION-A>Q 17
How is water purified on a large scale at water works? Explain with the help of a labelled diagram. Name the substance which is added to kill germs in the drinking water supply?
EASY
9th CBSE
IMPORTANT
Science for Ninth Class (Part-3) Biology>Chapter 9 - Model Test Paper 3>SECTION-A>Q 18
 Write the three equations of uniformly accelerated motion. Give the meaning of each symbol that occurs in them.
MEDIUM
9th CBSE
IMPORTANT
Science for Ninth Class (Part-3) Biology>Chapter 9 - Model Test Paper 3>SECTION-A>Q 19
If a balloon filled with air and its mouth untied, is released with its mouth in the downward direction, it moves upwards. Why?
HARD
9th CBSE
IMPORTANT
Science for Ninth Class (Part-3) Biology>Chapter 9 - Model Test Paper 3>SECTION-A>Q 19
An unloaded truck weighing 2000 kg has a maximum acceleration of 0.5 m s-2. What is the maximum acceleration when it is carrying a load of 2000 kg? 
HARD
9th CBSE
IMPORTANT
Science for Ninth Class (Part-3) Biology>Chapter 9 - Model Test Paper 3>SECTION-A>Q 20
Describe with a diagram the fluid mosaic organisation of the plasma membrane. 
HARD
9th CBSE
IMPORTANT
Science for Ninth Class (Part-3) Biology>Chapter 9 - Model Test Paper 3>SECTION-A>Q 21
Define muscular tissue. Classify and explain different types of muscles with the help of suitable diagrams. 
MEDIUM
9th CBSE
IMPORTANT
Science for Ninth Class (Part-3) Biology>Chapter 9 - Model Test Paper 3>SECTION-B>Q 22
Bromine and air take about 15 minutes to diffuse completely but bromine diffuses into a vacuum very rapidly. Why is this so?