CBSE Class 11 Physics solved practice paper is available here for download in PDF format. This paper contains important question from first ten chapters of **Class 11 Physics NCERT textbook**. The format of this question paper is similar to the latest CBSE Sample Paper. Questions in this paper are based on concepts given in first 10 chapters of Class 11 Physics NCERT textbook. This paper is important for CBSE Class 11 Physics half yearly exam.

*Format of CBSE Class 11 Physics Paper:*

(*a*) All questions are compulsory.

(*b*) There are 26 questions in total. Questions 1 to 5 carry one mark each; questions 6 to 10 carry two marks each, questions 11 to 22 carry three marks each, question 23 carry four marks and questions 24 to 26 carry 5 marks each.

(*c*) There is no overall choice. However, internal choices have been provided in some questions.

(*d*) Use of calculator is not permitted.

(*e*) You may use the following physical constants wherever necessary.

*Some randomly selected questions from CBSE Class 11 Physics Paper:*

**Question:** Can a quantity have dimensions, but still have no units?

**Solution:**

No, a quantity having dimension must possess some units

**Question:** Why a player lower’s his hand while taking a catch?

**Solution:**

As, *force acting on a body = rate of change of momentum = (change in momentum) / (time taken)*

By lowering his hands, he increases the interval in which the catch is taken. This increase in time interval results in the less rate of change of momentum. Therefore, in accordance with Newton’s second law of motion, less force acts on his hands and he saves himself from being hurt.

**CBSE Class 11 Physics Syllabus 2017 - 2018**

**Question:** The mass of an object on moon is 10 kg, what is its mass on earth?

**Solution:**

10 kg.

**Class 11th Physics NCERT Solutions**

**Question:** Write some assumptions made in the analysis of a projectile motion?

**Solution:**

The following assumptions are made while analyzing projectile motion:

(i) Air resistance is neglected

(ii) The acceleration due to gravity is assumed to be constant in magnitude and direction at all points of the motion of projectile.

(iii) The effect due to rotation of earth and curvature is neglected.

**Question:** Can a quantity have dimensions, but still have no units?

**Solution:**

No, a quantity having dimension must possess some units

**Question:** Which physical quantity is represented by the product of the moment of inertia and the angular velocity?

**Solution:**

Product of I and ω represents angular momentum.

**Question: **Write some assumptions made in the analysis of a projectile motion?

**Solution:**

The following assumptions are made while analyzing projectile motion:

(i) Air resistance is neglected

(ii) The acceleration due to gravity is assumed to be constant in magnitude and direction at all points of the motion of projectile.

(iii) The effect due to rotation of earth and curvature is neglected.

**Question: **Can two vectors of different magnitudes combined to give zero resultant? Will it be possible with the help of three vectors?

**Solution:**

No, two vectors of different magnitudes can’t have zero resultant. Yes.

**Question:** Is it possible that a body is in accelerated motion under a force acting on the body, yet no work is being done by the force. Give examples.

**Solution:**

Yes. For example, under centripetal force, a body moves uniformly in a circle with centripetal acceleration. But no work is done.

**Question:** What is the work done in blowing a soap bubble of radius r and surface tension S?

**Solution:**

Work done = surface tension × area of soap bubble = S × (4πr^{2}) × 2 = 8SL.

**Question:** A meteorite burns in the atmosphere before coming to the earth’s surface. What happens to its momentum?

**Solution:**

The momentum of the meteorite is transferred to the air molecules. Thus momentum conservation principle is not violated.

**Question: **What is the location of the centre of mass of a

(*i*) Sphere, (*ii*) Cylinder, (*iii*) Ring, and (*iv*) Cube, each of uniform mass density.

Does the centre of mass of a body necessarily lie on the body?

**Solution:**

In all the four cases, as the mass density is uniform, centre of mass is located at their respective geometrical centres.

No, it is not necessary that the centre of mass of a body should lie on the body. For example, in case of a circular ring, centre of mass is at the centre of the ring, where there is no mass.

**Download CBSE Class 11 Physics Solved Sample Paper 2017: Set – I**