Tags Class 12th

Class 12th

Get insights from 12k questions on Class 12th, answered by students, alumni, and experts. You may also ask and answer any question you like about Class 12th

Follow Ask Question

12k

Questions

Discussions

Active Users

Followers

New answer posted

6 months ago

Class 12th Maths

The sum of all the real roots of the equation $(e^{2 x} - 4) (6 e^{2 x} - 5 e^{x} + 1) = 0 i s$

0 Follower 5 Views

Payal Gupta

Contributor-Level 10

$e^{2 x} - 4 = 0 o r 6 e^{2 x} - 5 e^{x} + 1 = 0$

$\Rightarrow x = l n 2 x = l n (\frac{1}{3}), l n (\frac{1}{2})$

= $- l n 3, - l n 2$

0 0

New answer posted

6 months ago

Class 12th Physics

A circular coil of 1000 turns each with area 1m² is rotated about its vertical diameter at the rate of one revolution per second in a uniform horizontal magnetic field of 0.07 T. The maximum voltage generation will be ________V.

0 Follower 9 Views

Payal Gupta

Contributor-Level 10

given N = 1000 turns

A = 1m²

$ω = 1 r e v / s e c$

$= 1 * 2 π r a d / s e c$

$V = \frac{- d ?_{B}}{d t} = \frac{- d}{d t} (N B A c o s ω t)$

= $140 * \frac{22}{7}$

= 20 * 22

= 440 volts

0 0

New answer posted

6 months ago

Class 12th Physics

A ray of light is incident at an angle of incidence $60 °$ on the glass slab of refractive index $\sqrt[]{3} .$ After refraction, the light ray emerges out from other parallel faces and lateral shift between incident ray and emergent ray is $4 \sqrt[]{3}$ cm. The thickness of the glass slab is _______cm.

0 Follower 7 Views

Payal Gupta

Contributor-Level 10

$d = 4 \sqrt[]{3}$ cm (Lateral shift)

By Snell's law

$μ_{a i r} s i n 60 ° = μ_{g} s i n θ$

$\Rightarrow 1 * \frac{\sqrt[]{3}}{2} = \sqrt[]{3} s i n θ$

$s i n θ = \frac{1}{2}$

= 30°

$t a n 30 ° = \frac{d}{t} = \frac{4 \sqrt[]{3}}{t}$

$\Rightarrow \frac{1}{\sqrt[]{3}} = \frac{4 \sqrt[]{3}}{t}$

t = 12 cm

0 0

New answer posted

6 months ago

Class 12th Physics

A sample contains 10^-2kg each of two substances A and B with half lives 4s and 8s respectively. The ration of their atomic weights is 1 : 2. The ratio of the amounts of A and B after16s is $\frac{x}{100}$ . The value of x is ______.

0 Follower 4 Views

Payal Gupta

Contributor-Level 10

$f o r A, t_{\frac{1}{2}} = 4 s e c$

$= m A_{0} e^{-} \frac{0.693}{4} * 16$

$m_{A} = m_{A 0} e^{- 4 * 0.693}$ - (1)

for B,

for B, $t_{\frac{1}{2}} = 8 s e c$

$m_{B} = m_{B_{0}} e^{- 2 * 0.693}$ - (2)

$\frac{m_{A}}{m_{B}} = \frac{m_{A O}}{m_{B O}} \frac{e^{- 4} * 0.693}{e^{- 2} * 0.693}$

$\frac{m_{A}}{m_{B}} = \frac{25}{100} = \frac{x}{100} x = 25$

0 0

New answer posted

6 months ago

Class 12th Physics

In the given circuit, the value of current I_Lwill be _________mA. (When R_L = 1 k $Ω$ )

0 Follower 10 Views

Payal Gupta

Contributor-Level 10

$I_{L} = \frac{V}{R_{L}} = \frac{5}{1 k Ω}$

$l_{L} = 5 * 1 0^{- 3} A = 5 m A$

0 0

New answer posted

6 months ago

Class 12th Physics

A potentiometer wire of length 10m and resistance 20 $Ω$ is connected in series with a 25 V battery and an external resistance $30 Ω$ . A cell of emf E in secondary circuit is balanced by 250cm long potentiometer wire. The value of E (in volt) is $\frac{x}{10} .$ The value of x is ______.

0 Follower 3 Views

Payal Gupta

Contributor-Level 10

AB = 10 m

$R_{A B} = 20 Ω$

$L_{A C} = 250 c m$

= 2.5 m

$l = \frac{25}{20 + 30}$

$E = \frac{x}{10} = \frac{25}{10}$

0 0

New answer posted

6 months ago

Class 12th Physics

An antenna is placed in a dielectric medium of dielectric constant 6.25. If the maximum size of that antenna is 5.0 mm, it can radiate a signal of minimum frequency of ________ GHz.

(Given µ_r = 1 for dielectric medium)

0 Follower 4 Views

Payal Gupta

Contributor-Level 10

$v = \frac{C}{\sqrt[]{μ_{r} ε_{r}}} = \frac{3 * 1 0^{8}}{\sqrt[]{6.25 * 1}} = \frac{3 * 1 0^{8}}{2.5} = 1.25 * 1 0^{8} m / s e c$

$A s f λ = f (5 * 1 0^{- 3} * 4) = 1.25 * 1 0^{8} \Rightarrow f = 6.25 G H z$

So, $f \approx 6 .$

0 0

New answer posted

6 months ago

Class 12th Matrices

What are the types of triangular matrices?

0 Follower 1 View

Jaya Sharma

Contributor-Level 10

Apart from upper and lower triangular matrices, we have the unit triangular matrix, strictly-triangular matrix and an atomic-triangular matrix.

0 0

New answer posted

6 months ago

Class 12th Matrices

What are the other types of triangular matrices?

0 Follower 1 View

Jaya Sharma

Contributor-Level 10

A few types of matrices are row and column matrices, singleton, null matrix, square, diagonal, scalar, identity, equal, triangular (both upper and lower), singular and non-singular matrices, symmetric, skew-symmetric, hermitian, and orthogonal matrices. NCERT excercise on matrices chapter covers questions related to this topic

0 0

New answer posted

6 months ago

Class 12th Maths

Define Upper and Lower Triangular Matrices.

0 Follower 1 View

Jaya Sharma

Contributor-Level 10

An upper triangular matrix is a square matrix where all the elements above the diagonal are non-zero, and below it is zero. A lower triangular matrix is a square matrix where all the elements above the diagonal are zero.

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

Class 12th

Questions

Discussions

Active Users

Followers

All

Discussions

Unanswered Questions

Share Your College Life Experience