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.
A magnet held vertically, with its north pole down, is dropped along the axis of a closed solenoid placed vertically on a table. If the observer looks down from the top,

the induced current will flow in the anticlockwise direction.
the induced current will flow in the clockwise direction.
no induced current will flow in the solenoid.
the magnet will fall with a constant velocity.

View Solution

2.
Two point charges -Q and Q are located at points (d, 0) and (0, d) respectively, in x-y plane. The electric field E at the origin will be:

$\frac{1}{4\pi\epsilon_0} \frac{\sqrt{2}Q}{d^2} (\hat{i} - \hat{j})$
$\frac{1}{4\pi\epsilon_0} \frac{\sqrt{2}Q}{d^2} (-\hat{i} - \hat{j})$
$\frac{1}{4\pi\epsilon_0} \frac{Q}{d^2} (\hat{i} - \hat{j})$
$\frac{1}{4\pi\epsilon_0} \frac{Q}{d^2} (-\hat{i} - \hat{j})$

View Solution

3.
The number of free electrons per unit volume ($\text{m}^3$) in a wire made of copper (resistivity $1.72 \times 10^{-8}\,\Omega\,\text{m}$) is $8.5 \times 10^{28}$. Calculate the average number of collisions made by an electron in one second when an electric field is maintained in the wire.

View Solution

4.
Find the ratio $\dfrac{\lambda_\alpha}{\lambda_p}$ of the de Broglie wavelength $\lambda_\alpha$ associated with an alpha particle to the de Broglie wavelength $\lambda_p$ associated with a proton if both are moving with the same velocity.

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5.
(I) The real image of an object placed between $f$ and $2f$ from a convex lens can be seen on a screen placed at the image location. If the screen is removed, is the image still there? Explain.
(II) Plane and convex mirrors produce virtual images of objects. Can they produce real images under some circumstances? Explain.

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6.
A parallel beam of monochromatic light falls normally on a single slit of width $a$ and a diffraction pattern is observed on a screen placed at distance $D$ from the slit. Explain:
(I) the formation of maxima and minima in the diffraction pattern, and
(II) why the maxima go on becoming weaker and weaker with its increasing number $n$.

View Solution

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

1.
A magnet held vertically, with its north pole down, is dropped along the axis of a closed solenoid placed vertically on a table. If the observer looks down from the top,

2.
Two point charges -Q and Q are located at points (d, 0) and (0, d) respectively, in x-y plane. The electric field E at the origin will be:

3.
The number of free electrons per unit volume ($\text{m}^3$) in a wire made of copper (resistivity $1.72 \times 10^{-8}\,\Omega\,\text{m}$) is $8.5 \times 10^{28}$. Calculate the average number of collisions made by an electron in one second when an electric field is maintained in the wire.

4.
Find the ratio $\dfrac{\lambda_\alpha}{\lambda_p}$ of the de Broglie wavelength $\lambda_\alpha$ associated with an alpha particle to the de Broglie wavelength $\lambda_p$ associated with a proton if both are moving with the same velocity.

Similar Physics Concepts

Comments

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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

1.A magnet held vertically, with its north pole down, is dropped along the axis of a closed solenoid placed vertically on a table. If the observer looks down from the top,

2.Two point charges -Q and Q are located at points (d, 0) and (0, d) respectively, in x-y plane. The electric field E at the origin will be:

3.The number of free electrons per unit volume ($\text{m}^3$) in a wire made of copper (resistivity $1.72 \times 10^{-8}\,\Omega\,\text{m}$) is $8.5 \times 10^{28}$. Calculate the average number of collisions made by an electron in one second when an electric field is maintained in the wire.

4.Find the ratio $\dfrac{\lambda_\alpha}{\lambda_p}$ of the de Broglie wavelength $\lambda_\alpha$ associated with an alpha particle to the de Broglie wavelength $\lambda_p$ associated with a proton if both are moving with the same velocity.

Similar Physics Concepts

Comments

SUBSCRIBE TO OUR NEWS LETTER

1.
A magnet held vertically, with its north pole down, is dropped along the axis of a closed solenoid placed vertically on a table. If the observer looks down from the top,

2.
Two point charges -Q and Q are located at points (d, 0) and (0, d) respectively, in x-y plane. The electric field E at the origin will be:

3.
The number of free electrons per unit volume ($\text{m}^3$) in a wire made of copper (resistivity $1.72 \times 10^{-8}\,\Omega\,\text{m}$) is $8.5 \times 10^{28}$. Calculate the average number of collisions made by an electron in one second when an electric field is maintained in the wire.

4.
Find the ratio $\dfrac{\lambda_\alpha}{\lambda_p}$ of the de Broglie wavelength $\lambda_\alpha$ associated with an alpha particle to the de Broglie wavelength $\lambda_p$ associated with a proton if both are moving with the same velocity.