NCERT Solutions For Class 11 Physics Chapter 7: System of Particles and Rotational Motion

NCERT Solutions for Class 11 Physics Chapter 7 System of Particles and Rotational Motion covers all the concepts discussed in the Class 11 Physics Chapter 7. The combination of rotational motion and the translational motion of a rigid body is known as rolling motion. According to the law of conservation of angular momentum, if there is no external couple acting, the total angular momentum of a rigid body or a system of particles is conserved.

Class 11 Physics Chapter 7 System of Particles and Rotational Motion has a weightage of 17 marks along with Unit 4 Work, Energy, and Power and Unit 6 Gravitation. The Class 11 Physics Chapter 7 discusses the concepts of Torque, Angular Momentum, and Rotational Kinetic Energy.

Download PDF: NCERT Solutions for Class 11 Physics Chapter 7

NCERT Solutions for Class 11 Physics Chapter 7

Class 11 Physics Chapter 7 – Concepts Covered

Centre of Mass: For a system of particles, the centre of mass is the balancing point where the entire mass of the system is concentrated, for consideration of its translational motion.

If there are 2 particles with mass m1 and m2 with position vectors $\overrightarrow{r_1}\ and\ \overrightarrow{r_2}$, then the position vector of centre of mass is given as:

$\overrightarrow{r_{cm}} = {{m_1}\overrightarrow{r_{1}} + {m_2}\overrightarrow{r_{2}} \over m_1 + m_2}$

The cross product of two vectors $\overrightarrow{A}$ and $\overrightarrow{B}$ is another vector $\overrightarrow{C}$, which has a magnitude equal to the product of the magnitudes of 2 vectors and the sine of the smaller angle $\theta$ between them.

$\overrightarrow{A} \times \overrightarrow{B} = \overrightarrow{C} = ABsin\theta \hat{c}$

Torque or moment of force is the product of the magnitude of the force acting on a particle and the perpendicular distance of the application of this force from the axis of rotation of the particle.

$Torque = Force \times perpendicular\ distance$

The angular momentum about an axis of rotation is a vector quantity, with a magnitude equal to the product of the magnitude of momentum and the perpendicular distance of the line of action of momentum from the axis of rotation. Its direction is perpendicular to the plane that contains the momentum and the perpendicular distance.

$\overrightarrow{L} = \overrightarrow{r} \times \overrightarrow{p} $

Torque and angular momentum are correlated to each other.

$\tau = {\overrightarrow{dL} \over dt}$

Class 11 Physics Chapter 7 Related Guides:

Unit of Moment of Inertia	Angular Speed	Radial Acceleration
Relation Between Torque and Moment of Inertia	Angular Speed Formula	Angular Acceleration
Moment of Inertia	Rolling Motion	Unit of Moment of Inertia
Angular displacement	Angular speed	Radial Acceleration
Radius of Gyration	Rigid Bodies	Tangential Velocity Formula

Class 11 Physics Study Guides:

NCERT Solutions for Class 11 Physics	Difference between in Physics	Class 11 Physics Notes
Physics Formula	Physics Constants	SI Units in Physics
Derivations in Physics	Relation between articles in Physics	Physics Study Notes

CBSE CLASS XII Related Questions

1.
Capacitors are manufactured with certain standard capacitances and working voltages. However, these standard values may not be the ones that are actually needed in a particular application. Two or more capacitors can be grouped in series or in parallel to achieve desired capacitance and voltage. When connected in series, the total capacitance decreases while the voltage rating increases, whereas in parallel connections, the total capacitance increases and maintains the same voltage rating. A capacitor stores energy in the electric field between its plates and stored energy is proportional to the square of the voltage and capacitance $U = \frac{1}{2}CV^2$, where symbols have their usual meanings.
Two capacitors, one of $3 \ \mu$F and the other of $6 \ \mu$F, are connected in series in the circuit as shown in the figure, for a long time. }

2.
Two air-filled capacitors of capacitances $C_1$ and $C_2$ are connected in parallel with a dc battery. After the capacitors are fully charged, a slab of dielectric constant K is inserted between the plates of each capacitor. How will the (i) charge on each capacitor and (ii) energy stored in the capacitor affected after the slab is introduced.

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3.
Read the following paragraph and answer the questions that follow.
In an experiment with convex lens of focal length f, the screen is fixed at a distance D from the object. A student slowly moves the lens away from the object towards the screen and finds that she is able to form sharp image of the object for two positions of the lens. The distance between these two positions of the lens is d.

4.
Read the following paragraph and answer the questions that follow.
A p-type or n-type semiconductor can be converted into a p-n junction by doping it with suitable impurity. The motion of majority charge carriers causes diffusion current across the junction while the barrier electric field causes motion of minority carriers for drift current. In case of unbiased diode, the diffusion and drift currents are equal. This equilibrium is disturbed by the biasing batteries. Diodes, therefore, allow currents in one direction. This property of diode is used in making rectifiers.

5.
Two metal spheres of radii $r_1$ and $r_2$ ($> r_1$) having charges $q_1$ and $q_2$ respectively kept in air, are brought in contact. Which of the following statements is not correct ?

The total charge of the two spheres is conserved.
Both spheres attain the same potential.
The final potential of the system equals $\frac{1}{4\pi\epsilon_0} \frac{(q_1 + q_2)}{(r_1 + r_2)}$
The final potential of the system equals $\frac{1}{4\pi\epsilon_0} \frac{(q_1 + q_2) (r_1 + r_2)}{r_1 r_2}$

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6.
Write two advantages of reflecting telescope over refracting telescope.

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NCERT Solutions For Class 11 Physics Chapter 7: System of Particles and Rotational Motion

NCERT Solutions for Class 11 Physics Chapter 7

Class 11 Physics Chapter 7 – Concepts Covered

CBSE CLASS XII Related Questions

5.
Two metal spheres of radii $r_1$ and $r_2$ ($> r_1$) having charges $q_1$ and $q_2$ respectively kept in air, are brought in contact. Which of the following statements is not correct ?

6.
Write two advantages of reflecting telescope over refracting telescope.

Similar Physics Concepts

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NCERT Solutions For Class 11 Physics Chapter 7: System of Particles and Rotational Motion

NCERT Solutions for Class 11 Physics Chapter 7

Class 11 Physics Chapter 7 – Concepts Covered

CBSE CLASS XII Related Questions

5.Two metal spheres of radii $r_1$ and $r_2$ ($> r_1$) having charges $q_1$ and $q_2$ respectively kept in air, are brought in contact. Which of the following statements is not correct ?

6.Write two advantages of reflecting telescope over refracting telescope.

Similar Physics Concepts

Comments

SUBSCRIBE TO OUR NEWS LETTER

5.
Two metal spheres of radii $r_1$ and $r_2$ ($> r_1$) having charges $q_1$ and $q_2$ respectively kept in air, are brought in contact. Which of the following statements is not correct ?

6.
Write two advantages of reflecting telescope over refracting telescope.