Module 2 - MCQ Test, Class 9 Science - Class 9 MCQ

The spring force is the force exerted by a compressed or stretched spring upon any object that is attached to it. An object that compresses or stretches a spring is always acted upon by a force that restores the object to its rest or equilibrium position. So, the spring force does not always pushes a body.

If a branch of a tree is vigorously shaken, some of the leaves may get detached from tree due to inertia of rest. The leaves tend to remain in rest but branches come in motion.

At equilibrium, the acceleration is equal to zero. So, there is no net change in acceleration of the moving body.

Inflated balloon lying on the surface of a floor moves forward when pierced with a pin due to Newton’s third law of motion. The air coming out of the balloon forces the balloon in opposite direction.

The SI unit of force is Newton, which is equal to the mass/ acceleration. 
Newton = Kg/ms² = Kgms⁻².

Inertia is the property of a body by virtue of which the body unable to change the state of rest or state of motion and direction as inertia is the tendency to oppose the change in state or direction.

To every action, there is an equal and opposite reaction. This is the newton’s third law of motion.

The force acting on a body is equal to rate of change of momentum. Change of momentum = 10 Kg/s, time taken = 0.01 second. Force = 10/0.01 = 1000N.

One Newton (1N) is equal to 105 dyne. Both dyne and Newton is unit of force.

Inertia of the body is proportional to the mass of the body. 5Rs coin is heavier than 5Rs note and 1Rs coins. So, inertia of 5Rs coin more than others.

The most abundant element in earth’s crust is Oxygen. It is present in earth crust in form of oxide, carbonate etc. of metal.

The density of ice at its melting point is less than density of water. Ice have less density than water, that is why ice float on water.

The emulsifier which stabilizes milk emulsion is called Casein. Casein is found in mammalian milk, making up 80% of the protein in cow milk and between 20% and 45% of the protein in human milk.

22 carrot gold is homogenous mixture of 22 parts gold and 2 parts copper or silver. 22 carrot gold is pure gold and an element.

A substance that can be beaten into thin sheets and drawn into thin wire is both malleable and ductile. Gold is most malleable and ductile element.

The particle size of suspension is greater than 100 nm. So, particle size of substance ‘P’ present in water will be the suspension.

To separate two miscible liquids from a mixture having boiling point temperature difference of more than 2 degree, fractional distillation is used.

The major constituents of universe are Hydrogen and Helium. They are constituent of Sun, stars and other solar bodies.

Clouds and fogs are example of liquid in gas solution. Cloud is formed by combination of water vapour with dust particles. Fogs contain water vapour and gases.

Alveolar tissue is known as packaging tissue. These tissues are responsible for storing materials not required by our body at particular time like glycogen.

Complex tissue consists of different types of cells carrying out the same function. They help in transportation of organic material ,water and minerals.In plants xylem and phloem are example of complex tissues.

Epidermis in plants provides protection, regulation of transpiration and formation of insulation stationary air layer with the help of hair on the surface of it.

Bone consists of cells called Osteocytes. Bone is a specialized connective tissue. Osteocytes are present between the lamellae in fluid filled spaces called lacunae.

Heart muscles are called cardiac muscles. These muscles are involuntary, striated and uninulcleate. Cardiac tissue pumps blood form birth till death.

Complex tissue consists of different types of cells carrying out the same function. They help in transportation of organic material ,water and minerals.In plants xylem and phloem are example of complex tissues.

The husk of coconut is made up of sclerenchyma tissue. Sclerenchyma is simple permanent tissue that provides mechanical support to parts of the plant.

Blood is flood connective tissue that helps in transport of oxygen and carbon dioxide. Haemoglobin present in RBC is responsible for oxygen transport.

Squamous epithelium tissue is found in alveoli of lung and other parts of plants where regular contraction and relaxation takes place.

Phloem is complex tissue consists of sieve tube, companion cells, phloem parenchyma and phloem sclerenchyma (fibre). In which phloem sclerenchyma is non-living.