Tags Physics

Physics

Get insights from 5.6k questions on Physics, answered by students, alumni, and experts. You may also ask and answer any question you like about Physics

Follow Ask Question

5.6k

Questions

Discussions

Active Users

Followers

New answer posted

a year ago

Physics Physics NCERT Exemplar Solutions Class 11th Chapter Eleven

Mark the correct options:

(a) A system X is in thermal equilibrium with Y but not with Z. System Y and Z may be in thermal equilibrium with each other

(b) A system X is in thermal equilibrium with Y but not with Z. Systems Y and Z are not in thermal equilibrium with each other

(c) A system X is neither in thermal equilibrium with Y nor with Z. The systems Y and Z must be in thermal equilibrium with each other

(d) A system X is neither in thermal equilibrium with Y nor with Z. The system Y and Z may be in thermal equilibrium with each other

0 Follower 4 Views

Payal Gupta

Contributor-Level 10

This is a multiple choice answer as classified in NCERT Exemplar

(b), (d) T_x=T_y when x and y are in thermal equilibrium.

T_{x
$\neq$}T_Zwhen x and z are not in thermal equilibrium.

T_{y
$\neq$}T_Z

Hence y and z are not In thermal equilibrium.

Given T_{x
$\neq$}T_y

And T_{x
$\neq$}T_Z

We cannot say about equilibrium of y and z.

They may or may not in thermal equilibrium

0 0

New answer posted

a year ago

Physics physics ncert exemplar solution class 12th chapter one

A point positive charge is brought near an isolated conducting sphere. The electric field is best given by.

0 Follower 47 Views

alok kumar singh

Contributor-Level 10

This is a Multiple Choice Questions as classified in NCERT Exemplar

Answer- (a)

Explanation- when a positive point charge is brought near an isolated conducting sphere without touching the sphere, then the free electron in the sphere are attracted towards the positive charge. This leaves an excess positive charge on right side of sphere . And also by induction the negative charge is setup across left side. So field lines first goes from positive charge (+q) to negative charge of sphere then from positive charge of sphere to negative charge anywhere in the universe.

0 0

New answer posted

a year ago

Physics Physics NCERT Exemplar Solutions Class 11th Chapter Eleven

A sphere, a cube and a thin circular plate, all of same material and same mass are initially heated to same high temperature.

(a) Plate will cool fastest and cube the slowest

(b) Sphere will cool fastest and cube the slowest

(c) Plate will cool fastest and sphere the slowest

(d) Cube will cool fastest and plate the slowest.

0 Follower 9 Views

Payal Gupta

Contributor-Level 10

This is a multiple choice answer as classified in NCERT Exemplar

According to Stefan's law H $\propto$ AT⁴ where A is the area and T is the temperature

H_sphere:H_cube:H_plate= A_sphere:A_cube:A_plate

As A_plate is maximum.

Hence the plate will cool the fastest.

0 0

New answer posted

a year ago

Physics physics ncert exemplar solution class 12th chapter one

In figure two positive charges q₂ and q₃ fixed along the y-axis, exert a net electric force in the +x-direction on a charge q₁, fixed along the x-axis. If a positive charge Q is added at (x, 0), the force on q₁

(a) Shall increase along the positive x-axis
(b) Shall decrease along the positive x-axis
(c) Shall point along the negative x-axis
(d) Shall increase but the direction changes because of the intersection of Q with q₂ and q₃

0 Follower 16 Views

alok kumar singh

Contributor-Level 10

This is a Multiple Choice Questions as classified in NCERT Exemplar

Answer. (a)

Explanation-The force between (q1, q2) and (q1, q3) is must be attractive to net forces act in positive direction of x . so q1 must be negative. But if we place a positive charge Q in positive direction of x then it must be attractive towards along x-axis. So it will be attractive towards positive x axis.

0 0

New answer posted

a year ago

Physics Physics NCERT Exemplar Solutions Class 11th Chapter Eleven

The radius of a metal sphere at room temperature T is R, and the coefficient of linear expansion of the metal is α. The sphere is heated a little by a temperature ?T so that its new temperature is T+ ?T. The increase in the volume of the sphere is approximately

(a) 2παR?T

(b) πR²α?T

(c) 4πR³?T/3

(d) 4παR³ $α$ ?T

0 Follower 10 Views

Payal Gupta

Contributor-Level 10

This is a multiple choice answer as classified in NCERT Exemplar

(d) Let radius of sphere be R . as the temperature increases radius of the sphere increases.

Original volume V_o= $\frac{4}{3} π R$ ³

Coefficient linear expansion = $α$

Coefficient of volume expansion =3 $α$

$\frac{d V}{V d T} =$ 3 $α$ , dV= 4 $π$ R³ $α ? T$ =increase in volume

0 0

New answer posted

a year ago

Physics physics ncert exemplar solution class 12th chapter one

Figure shows the electric field lines around three point charges A, B and C.

(i) Which charges are positive?
(ii) Which charge has the largest magnitude? Why?
(iii) In which region or regions of the picture could the electric field be zero? Justify your answer.
(a) Near A (b) Near B
(c) Near C (d) Nowhere

0 Follower 38 Views

alok kumar singh

Contributor-Level 10

This is a Short Answer Type Questions as classified in NCERT Exemplar

Explanation-The electric lines of forces always starts from a positive charge and ends at a negative charge. In case of a single isolated charge, electric lines of force start from positive charge ends at infinity.

(i) Here, in the figure, the electric lines of force starts from A and C. Therefore, charges A and C must be positive.

(ii) The number of electric lines of forces starting from charge C are maximum, so C must have the largest magnitude.

(iii) From the figure we see that a neutral point exists between charges A and

Here, more number of elect

...more

0 0

New answer posted

a year ago

Physics Physics NCERT Exemplar Solutions Class 11th Chapter Eleven

Heat is associated with

(a) Kinetic energy of random motion of molecules

(b) Kinetic energy of orderly motion of molecules

(c) Total kinetic energy of random and orderly motion of molecules

(d) Kinetic energy of random motion in some cases and kinetic energy of orderly motion in other

0 Follower 5 Views

Payal Gupta

Contributor-Level 10

This is a multiple choice answer as classified in NCERT Exemplar

(a) We know that temperature increases vibrations of molecules about their mean position increases. Hence kinetic energy associated with random motion of molecules increases.

0 0

New answer posted

a year ago

Physics Physics NCERT Exemplar Solutions Class 11th Chapter Eleven

As the temperature is increased, the time period of a pendulum

(a) Increases as its effective length increases even though its centre of mass still remains at the centre of the bob

(b) Decreases as its effective length increases even though its centre of mass still remains at the centre of the bob

(c) Increases as its effective length increases due to shifting of centre of mass below the centre of the bob

(d) Decreases as its effective length remains same but the centre of mass shifts above the centre of the bob

0 Follower 3 Views

Payal Gupta

Contributor-Level 10

This is a multiple choice answer as classified in NCERT Exemplar

As the temperature is increased length of the pendulum increases.

T=2 $π \sqrt[]{\frac{L}{g}}$

So if we increase L then T also increases.

0 0

New answer posted

a year ago

Physics physics ncert exemplar solution class 12th chapter one

Two charges q and -3q are placed fixed on x-axis separated by distance d. where should a third charge 2q be placed such that it will not experience any force?

0 Follower 37 Views

alok kumar singh

Contributor-Level 10

This is a Short Answer Type Questions as classified in NCERT Exemplar

Answer = $\frac{d}{2}$ (1+ $\sqrt[]{3}$ ) towards left.

Explanation -lets consider 2q charge is placed in between q and -3q, here it will definitely experience some force q charge repel 2q charge and -3q charge will attract 2q charge. So 2q charge will move towards -3q charge.

Now lets consider it to the left of q at some distance x, here the force experience by q is repulsive and force experience by -3q is attractive . so they cancel out each other and no net force is experience by 2q.

Thus, force of attraction by -3q = force of repulsion by q

$?$ k 2q q/x² = k 2q 3q/ (x+d)²

$?$ (x+d)² = 3x

...more

This is a Short Answer Type Questions as classified in NCERT Exemplar

Answer = $\frac{d}{2}$ (1+ $\sqrt[]{3}$ ) towards left.

Thus, force of attraction by -3q = force of repulsion by q

$?$ k 2q q/x² = k 2q 3q/ (x+d)²

$?$ (x+d)² = 3x²

$?$ x² + d² + 2xd = 3x²

$?$ 2x² - 2dx – d² = 0

$?$ x = $\frac{d}{2}$ + $\frac{\sqrt[]{3} d}{2}$

$?$ x= $\frac{d}{2}$ (1+ $\sqrt[]{3}$ ) towards left.

less

0 0

New answer posted

a year ago

Physics Physics NCERT Exemplar Solutions Class 11th Chapter Eleven

An aluminium sphere is dipped into water. Which of the following is true?

(a) Buoyancy will be less in water at 0°C than that in water at 4°C.

(b) Buoyancy will be more in water at 0°C than that in water at 4°C.

(c) Buoyancy in water at 0°C will be same as that in water at 4°C.

(d) Buoyancy may be more or less in water at 4°C depending on the radius of the sphere.

0 Follower 10 Views

Payal Gupta

Contributor-Level 10

This is a multiple choice answer as classified in NCERT Exemplar

(a) F= V $ρ G$

F $\propto ρ$

$F_{4^{0} C} > F_{0^{0} C}$

Hence buoyancy will be less in water at 0⁰C than that in water at 4⁰C.

0 0

Get authentic answers from experts, students and alumni that you won't find anywhere else

On Shiksha, get access to

67k Colleges
1.2k Exams
718k Reviews
1850k Answers

Community GuidelinesUser Points System

QuestionsDiscussionsTags

Need guidance on career and education? Ask our experts

Your Question

Physics

Questions

Discussions

Active Users

Followers

All

Discussions

Unanswered Questions

Share Your College Life Experience