CBSE 11TH PHYSICS - Online Test

Q1. The scalar product of two vectors A and B is
Answer : Option C
Explaination / Solution:

Scalar product means dot product and dot product of 2 vectors gives a scalar , example dot product of force and displacement gives work which is scalar

Q2. The basic difference between a scalar and vector is one of
Answer : Option B
Explaination / Solution:

Scalar quantity gives you an idea about how much of an object there is, but vector quantity gives you an indication of how much of an object there is and that also in which direction. So, the main difference between these two quantities is associated with the direction, i.e. scalars do not have direction but vectors do.

Q3. The picture of heat as a fluid was discarded in favor of the modern concept of heat as a form of energy because
Answer : Option C
Explaination / Solution:

If heat were actually a substance, as many scientists of the time believed, it was difficult to see how so much of it could be produced during the boring of a metal cannon. Rumford showed that the amount of heat was not related to the quantity of filings produced

Q4. A perfectly rigid body is one
Answer : Option A
Explaination / Solution:

A perfectly rigid body is hypothetical in nature but for some phenomena ( in rotational bodies ) we assume bodies are perfectly rigid i.e. the intermolecular forces are always in equilibrium irrespective of the external forces due to which their shape and size are constant.

Q5. force is required
Answer : Option D
Explaination / Solution:

force is required to start a stationary object and to stop a moving object due to inertia. Inertia is a property of matter by which it continues in its existing state of rest or uniform motion in a straight line, unless that state is changed by an external force. This is also called law of inertia or newton's first law of motion

Q6. Density is defined as
Answer : Option C
Explaination / Solution:

Density is defined as the compactness of substance.

Mathematically,

Density(D)= 


Q7. Kinetic theory
Answer : Option B
Explaination / Solution:

The kinetic theory describes a gas as a large number of submicroscopic particles (atoms or molecules), all of which are in constant rapid motion that has randomness arising from their many collisions with each other and with the walls of the container. It will applicable only for gases

Q8. Heat flows from one body to another if
Answer : Option B
Explaination / Solution:

Heat is the amount of energy flowing from one body of matter to another spontaneously due to their temperature difference.

Q9. Measurement of a physical quantity is essentially the
Answer : Option B
Explaination / Solution:

The Measurement of a given quantity is essentially an act or result of comparison between a quantity whose magnitude (amount) is unknown, with a similar quantity whose magnitude (amount) is known, the latter quantity being called a Standard.

Q10. Oscillatory motion is best described by
Answer : Option A
Explaination / Solution:

In oscillatory motion object moves to and fro about mean position periodically or after a particular interval of time.All oscillatory motions are periodic in nature.