CBSE 11TH PHYSICS - Online Test
Q1. According to Kepler’s Law of areas,
Answer : Option A
Explaination / Solution:
Kepler law of areas describes the speed of a planet travelling in an elliptical orbit around the sun. A planet’s orbital speed changes, depending on how far it is from the Sun. The closer a planet is to the Sun, the stronger the Sun’s gravitational pull on it, and the faster the planet moves. The farther it is from the Sun, the weaker the Sun’s gravitational pull, and the slower it moves in its orbit. So, statement of Kepler's law of area is "The line joining the sun to the planet sweeps out equal areas in equal interval of time". i.e. areal velocity is constant.
Q2. for motion in a straight line
Answer : Option A
Explaination / Solution:
To describe motion along a straight line, we can choose an axis, say X-axis, so that it coincides with the path of the object. We then measure the position of the object with reference to a conveniently chosen origin, say O, Positions to the right of O are taken as positive and to the left of O, as negative.
Q3. When we make a mobile telephone call to a friend
Answer : Option D
Explaination / Solution:
Because mobile communication is a space communication and in space communication basically electromagnetic waves are used (as carrier waves as in case of radio communication) because of the modulation ( frequency, amplitude) operations which can be performed on EM waves. Thus when our friend receives the call, he also receives EM waves which is the carrier of our audio signals.
Q4. In pure translational motion of a rigid body
Answer : Option C
Explaination / Solution:
In translational motion when the body moves along a straight line or more exactly when every point of the body travels on paralell lines, thus at any instant of time every particle of the body has the same velocity.
Q5. The word Science originates from the Latin verb Scientia meaning
Answer : Option B
Explaination / Solution:
The phrase "scientia potentia est" (or "scientia est potentia" or also "scientia potestas est") is a Latin aphorism meaning "knowledge is power"
Q6. The scalar product of two vectors A and B in terms of the magnitudes and angle is
Answer : Option A
Explaination / Solution:
The scalar product of two vectors can be constructed by taking the component of one vector in the direction of the other and multiplying it times the magnitude of the other vector. This can be expressed in the form
Q7. Vectors can be added by
Answer : Option A
Explaination / Solution:
The sum of two or more vectors is called the resultant. The resultant of two vectors can be found using either the triangle method or the parallelogram method.
Q8. Thermodynamics is the branch of physics that deals with.
Answer : Option B
Explaination / Solution:
Thermodynamics is a branch of physics concerned with heat and temperature and their relation to energy and work. It deals with the relations between heat and other forms of energy (such as mechanical, electrical, or chemical energy), and, by extension, of the relationships between all forms of energy.
Q9. Elasticity is the property of a body, by virtue of which
Answer : Option C
Explaination / Solution:
When external force is applied on the solid bodies, the solid bodies get deformed. The atoms or molecules are displaced from their equilibrium positions causing a change in the interatomic ( or intermolicular ) distances. When the deforming foce is removed, the interatomic forces tend to drive them back to their original postions. Thus the body regains its original shape and size.
Q10. According to first law of motion
Answer : Option C
Explaination / Solution:
If net force act on a body then acceleration of the body will also be zero.Hence velocity will not be changed i.e. it continues in its existing state of rest or uniform motion in a straight line.
