CBSE 11TH PHYSICS - Online Test

Answer : Option C
Explaination / Solution:
No Explaination.

Answer : Option C
Explaination / Solution:

The area under the velocity-time curve between times t​​​​​​1 and t​​​​​​2 is equal to the displacement of the object during that interval of time.

Answer : Option B
Explaination / Solution:
No Explaination.

Answer : Option A
Explaination / Solution:

Gravitational Force

F=mg

⇒F=5×10.7=53.5 N

Answer : Option D
Explaination / Solution:

(i) PQ = diameter = displacement for each girl = 2r = 2 x 200 = 400 m Since, displacement vector does not depend upon the actual path length and it is the shortest distance between initial and final position, so in the case of each girl the displacement is 400 m. (ii)This is equal to the actual length of the path skated by girl B.

Answer : Option D
Explaination / Solution:
No Explaination.

Answer : Option C
Explaination / Solution:

Irreversible process is one which can be reversed in such a way that all changes taking place in the direct process are exactly replaced in the inverse order and opposite sense and no changes are left behind.

Answer : Option C
Explaination / Solution:

Work done is positive when force applied and displacement are in same direction.

W=F⃗ .s⃗ =Fscosθ

in this case angle between force and displacement is zero (i.e. cosθ=1) so that work done is positive.

Answer : Option C
Explaination / Solution:

Weight of the stone is balanced by the reaction of the floor. The only acceleration is provided by the horizontal motion of the train.

a = 1ms-2

force in horizontal direction 

F = ma = 0.1 x 1 = 0.1N

Answer : Option D
Explaination / Solution:

A model is a representation of something that is often too difficult (or impossible) to display directly. While a model's design is justified using experimental information, it is only accurate under limited situations. An example is the commonly used "planetary model" of the atom, in which electrons are pictured as orbiting the nucleus, analogous to the way planets orbit the Sun. We cannot observe electron orbits directly, but the mental image helps explain the observations we can make, such as the emission of light from hot gases. Physicists use models for a variety of purposes.