Class 12th

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New answer posted

a year ago

0 Follower 4 Views

P
Payal Gupta

Contributor-Level 10

This is a long answer type question as classified in NCERT Exemplar

Suppose the distance between the plates is d and applied voltage is Vt= V02

Then electric field is E= V d sin(2 π v t )

Jc= 1 ρ V 0 d s i n ( 2 π v t )

  =  J 0 c s i n 2 π v t

J 0 c   = V 0 ρ d

Jd= ε d E d t = V 0 ρ d

   = ε 2 π v V 0 d cos(2 π v t )

   = J0d cos 2 π v t

J0d= 2 π V ε V 0 d

J 0 d J 0 c = 2 πVερ = 2 π80ε0 v * 0.25 = 4 πε0 v *10 =4/9

New answer posted

a year ago

0 Follower 3 Views

P
Payal Gupta

Contributor-Level 10

This is a long answer type question as classified in NCERT Exemplar

E= λ e s 2 π ε 0 a j

And B= μ 0 i 2 π a i= μ 0 λ v 2 π a i

Then S= 1 μ 0 {E * B }= 1 μ 0 { λ j 2 π ε 0 a * μ 0 i 2 π a λ i }

 = λ 2 v 4 π 2 ε 0 a 2 j * i = - λ 2 v 4 π 2 ε 0 a 2 k

New answer posted

a year ago

0 Follower 7 Views

S
Shailja Choudhury

Contributor-Level 7

Yes, passing Class 12 is mandatory in order to secure admission to Techno India University. Students seeking for admission to UG or PG courses at the college must qualify for Class 12 with minimum 50-55% aggregate in Class 12.

New answer posted

a year ago

0 Follower 4 Views

A
alok kumar singh

Contributor-Level 10

This is a Multiple Choice Questions as classified in NCERT Exemplar

Answer- (b)

Explanation-as we know that λ = h 2 m k

so λ inversely proportional to m

so from the above conclusion we can say that λ alpha < λ p = λ n < λ e

New answer posted

a year ago

0 Follower 2 Views

A
alok kumar singh

Contributor-Level 10

This is a Multiple Choice Questions as classified in NCERT Exemplar

Answer- (c)

Explanation- In Davisson-Germer experiment, the de-Broglie wavelength associated with electron is

λ = 12.27/ V

Å . (i)where V is the applied voltage.

If there is a maxima of the diffracted electrons at an angle θ, then

2dsinθ = λ … (ii)

From Eq. (i), we note that if V is inversely proportional to the wavelength λ.

i.e., V will increase with the decrease in the λ.

From Eq. (ii), we note that wavelength λ is directly proportional to sinθ and hence θ.

So, with the decrease in λ, θ will also decrease.

Thus, when the voltage applied to A is increased. The dif

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New answer posted

a year ago

0 Follower 3 Views

A
alok kumar singh

Contributor-Level 10

This is a Multiple Choice Questions as classified in NCERT Exemplar

Answer- (d)

explanation- When a beam of electrons of energy E0 is incident on a metal surface kept in an

evacuated chamber electrons can be emitted with maximum energy E0 (due to elastic

collision) and with any energy less than E0, when part of incident energy of electron is

used in liberating the electrons from the surface of metal.

New answer posted

a year ago

0 Follower 3 Views

A
alok kumar singh

Contributor-Level 10

This is a Multiple Choice Questions as classified in NCERT Exemplar

Answer – (b)

Explanation- E=hc/ λ

And l = hc/E= 1240/106= 1.24 * 10-3nm

New answer posted

a year ago

0 Follower 4 Views

A
alok kumar singh

Contributor-Level 10

This is a Multiple Choice Questions as classified in NCERT Exemplar

Explanation- velocity of a freely falling body is v= 2 g h

And λ = h m v = h m 2 g h

λ = h -1

New answer posted

a year ago

0 Follower 2 Views

P
Pallavi Pathak

Contributor-Level 10

Yes, if one study from the moving charges and magnetism NCERT PDF given here they save a lot of time. They must practice all short answers questions and multiple choice questions to quickly cover all the topics of the chapter and improve their understanding of key concepts. The PDF is excellent for revision and it contains various application-based and conceptual questions with solutions. It reinforces the concepts, important formulas, and problem-solving techniques, making it ideal material for quick revision. After solving these questions thoroughly, the students will able to avoid the common mistakes related to chapter and there wil

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New answer posted

a year ago

0 Follower 6 Views

P
Pallavi Pathak

Contributor-Level 10

It is advisable that students first start with the NCERT textbook to understand the concepts and then practice the NCERT exemplars to master the concepts and understand where and how to use the concepts and formulas for solving various kinds of problems. As the exemplar includes all type of questions from short answer questions to MCQs. These helps in better concept clarity and especially MCQ questions help students to be ready for various entrance exams.
Practicing from exemplar increases your chance to score high in the exams. However, it is advisable to also practice additional numerical problems to tackle advanced-level questions an

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