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

5 months ago

Physics Class 12th

Five equal resistances are connected in a network as shown in figure. The net resistance between the points A and B is

0 Follower 11 Views

Payal Gupta

Contributor-Level 10

0 0

New answer posted

5 months ago

Physics Class 11th

The length of metallic wire is $l_{1}$ $_{}$ when tension in it is $T_{1}$ $_{}$ . It is $l_{2}$ $_{}$ when the tension is T2. The original length of the wire will be:

0 Follower 2 Views

Vishal Baghel

Contributor-Level 10

Stress = Y * strain

=> $\frac{T_{1}}{A} = Y * - \frac{(l_{1} - l)}{l} (i)$

$\frac{T_{2}}{A} = Y * \frac{(l_{2} - l)}{l} (i i)$

=> $\frac{T_{1}}{T_{2}} = \frac{l_{1} - l}{l_{2} - l}$

$\Rightarrow l = \frac{T_{1} l_{2} - T_{2} l_{2}}{T_{1} - T_{2}} = \frac{T_{2} l_{1} - T_{1} l_{2}}{T_{2} - T_{1}}$

0 0

New answer posted

5 months ago

Physics Physics Atoms

If $λ_{1} a n d λ_{2}$ are the wavelengths of the third member of Lyman and first member of Paschen series respectively, then the value of $λ_{1} : λ_{2} i s :$

0 Follower 2 Views

Payal Gupta

Contributor-Level 10

Lyman Series n_f = 1, ni = 2, 3.

Paschen series n_f = 3, ni = 4, 5, 6 -

$\frac{1}{λ_{1}} = R Z^{2} (\frac{1}{1^{2}} - \frac{1}{4^{2}})$

$\frac{1}{λ_{2}} = R Z^{2} (\frac{1}{3^{2}} - \frac{1}{4^{2}})$

$\frac{1 / λ_{1}}{1 / λ_{2}} = \frac{1 - \frac{1}{16}}{\frac{1}{9} - \frac{1}{16}} \Rightarrow \frac{λ_{2}}{λ_{1}} = \frac{\frac{15}{16}}{\frac{7}{9 * 16}} = \frac{15 * 9}{7} \Rightarrow \frac{λ_{1}}{λ_{2}} = \frac{7}{135}$

0 0

New answer posted

5 months ago

Physics Physics Alternating Current

An alternating is given by the equation i = i₁ $s i n ω t + i_{2} c o s ω t .$ Then rms current will be

0 Follower 3 Views

Payal Gupta

Contributor-Level 10

$l = l_{1} s i n ω t + l_{2} c o s ω t = \sqrt[]{l_{1}^{2} + l_{2}^{2}} [(\frac{l_{1}}{\sqrt[]{l_{1}^{2} + l_{2}^{2}}}) s i n ω t + \frac{l_{2}}{\sqrt[]{l_{1}^{2} + l_{2}^{2}}} c o s ω t]$

$= \sqrt[]{l_{1}^{2} + l_{2}^{2}} s i n (ω t + α) = l_{0} s i n (ω t + α$

$l_{r m s} = \frac{l_{0}}{\sqrt[]{2}} = \frac{\sqrt[]{l_{1}^{2} + l_{2}^{2}}}{\sqrt[]{2}}$

0 0

New answer posted

5 months ago

Physics Physics Motion in Plane

A planet revolving in elliptical orbit has:

(A) a constant velocity of revolution.

(B) has the least velocity when it is nearest to the sun.

(C) its areal velocity is directly proportional to its velocity.

(D) areal velocity in inversely proportional to its velocity.

(E) To follow a trajectory such that the areal velocity is constant.

Choose the correct answer from the options given below

0 Follower 3 Views

Payal Gupta

Contributor-Level 10

In elliptical orbit, areal velocity is constant

0 0

New answer posted

5 months ago

Physics Class 11th

The trajectory of a projectile in an vertical plane is y = αx - βx², where α and β are constants and x & y are respectively the horizontal and vertical distances of the projectile from the point of projection. The angle of projection θ and the maximum height attained H are respectively given by:

0 Follower 18 Views

Vishal Baghel

Contributor-Level 10

$y = α x - β x^{2}$

$\Rightarrow \frac{d y}{d x} = α - 2 β x = 0$

$\Rightarrow x = \frac{α}{2 β}$

$y_{m a x} = α * \frac{α}{2 β} - β * {(\frac{α}{2 β})}^{2} = \frac{α^{2}}{4 β}$

Range = $2 x = \frac{α}{β} = \frac{2 u^{2} s i n θ . c o s θ}{g}$

On comparing with

y = x tan θ - $\frac{g x^{2}}{2 u^{2} c o s^{2} θ}$

0 0

New answer posted

5 months ago

Physics System of Particles and Rotational Motion

A cord is wound round the circumference of wheel of radius r. The axis of the wheel is horizontal and the moment of inertial about it is I. A weight mg is attached to the cord at the end. The weight falls from rest. After falling through a distance 'h', the square of angular velocity of wheel will be:

0 Follower 4 Views

Vishal Baghel

Contributor-Level 10

mg – T = ma. (1)

T * R = l . (2)

a = R. (3)

With the help of equations (1), (2) and (3), we get

$a = \frac{m g}{m + \frac{l}{R^{2}}}$

$v = \sqrt[]{2 a h} = ω R$

$\Rightarrow ω^{2} = \frac{2 m g h}{l + m R^{2}}$

0 0

New answer posted

5 months ago

Physics Physics Oscillations

If two similar spring each of spring constant K₁ are joined in series, the new spring constant and time period would be changed by a factor

0 Follower 2 Views

Payal Gupta

Contributor-Level 10

T $1 = 2 π \sqrt[]{\frac{m}{k}}$

$k_{e q} = \frac{k * k}{k + k} = \frac{k}{2}$

$T_{2} = 2 π \sqrt[]{\frac{m}{(k / 2)}} = 2 π \sqrt[]{\frac{2 m}{k}}$

$\Rightarrow \frac{T_{2}}{T_{1}} = \sqrt[]{2} a n d \frac{k_{2}}{k_{1}} = \frac{1}{2}$

0 0

New answer posted

5 months ago

Physics Class 12th

The temperature q at the junction of two insulating sheets,having thermal resistances R₁ and R₂ as well top and bottom temperatures q₁ and q₂ (as shown in figure) is given by

0 Follower 9 Views

Payal Gupta

Contributor-Level 10

taking θ₁ > θ₂

Heat current = $\frac{θ_{1} - θ}{R_{1}} = \frac{θ - θ_{2}}{R_{2}} \Rightarrow \frac{θ_{1}}{R_{1}} + \frac{θ_{2}}{R_{2}} = θ (\frac{1}{R_{1}} + \frac{1}{R_{2}})$

$\Rightarrow θ = \frac{θ_{1} R_{2} + θ_{2} R_{1}}{R_{1} + R_{2}}$

0 0

New answer posted

5 months ago

Physics Class 12th

LED is constructed from Ga – As – P semiconducting material. The energy gap of this LED is 1.9 eV. Calculate the wavelength of light emitted and its colour.

[h = 6.63 * 10^-34 Js and c = 3 * 10⁸ ms^-1]

0 Follower 7 Views

Payal Gupta

Contributor-Level 10

$λ = \frac{h c}{E} = \frac{6.63 * 1 0^{- 34} * 3 * 1 0^{8}}{1.9 * 1.6 * 1 0^{- 19}}$ = 654 nm (red)

0 0

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

On Shiksha, get access to

66k Colleges
1.2k Exams
681k Reviews
1800k 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