Class 12th

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New answer posted

a year ago

0 Follower 3 Views

V
Vishal Baghel

Contributor-Level 10

(A) Source of microwave frequency   => Magnetron

(B) Source of infrared frequency                =>Vibration of atoms and molecules

(C) Source of Gamma rays                           => Radioactive decay of nucleus

(D) Source of x-rays                                      => inner shell electrons.

 

New answer posted

a year ago

0 Follower 11 Views

P
Payal Gupta

Contributor-Level 10

1+α2=1⇒α=0

&α2+β2=1⇒β2=±1

&α−αβ=0⇒α (1−β)=0⇒α=0  or  β=1

= 0 & = 1 or = 0 & = 1

4 + 4 = 1

New answer posted

a year ago

0 Follower 41 Views

A
alok kumar singh

Contributor-Level 10

A = [ x y z y z x z x y ] , | A | = 3 x y z − ( x 3 + y 3 + z 3 ) = − ( x + y + z ) [ ( x + y + z ) 2 − 3 ( x y + y z + z x ) ]

A2 = l

A. A' = l    (as A = A')

∴ x 2 + y 2 + z 2 = 1     a n d     x y + y z + z x = 0         

x 3 + y 3 + z 3 = 3 * 2 + 1 * ( 1 − 0 ) = 7             

New answer posted

a year ago

0 Follower 2 Views

V
Vishal Baghel

Contributor-Level 10

V = 1.24 * 106 volt

λ m i n = ?

λ m i n = h c e V = 1 2 4 2 n m e ( 1 . 2 4 * 1 0 6 ) = 1 0 0 0 * 1 0 − 9 1 0 6 ⇒ λ m i n = 1 0 − 3 n m

New answer posted

a year ago

0 Follower 5 Views

A
alok kumar singh

Contributor-Level 10

a → = i ^ + 2 j ^ − k ^ , b → = i ^ − j ^ , c → = i ^ − j ^ − k ^      

-> r → * a → = c → * a →

r → = c → + λ a →

Now, 0 = b → . c → + λ a → . b → a s     r → . b → = 0  

λ = − b → . c → a → . b → = 2        

∴ r → . a → = a → . c → + 2 a 2 = 1 2           

New answer posted

a year ago

0 Follower 21 Views

A
alok kumar singh

Contributor-Level 10

[ 0 − t a n θ 2 t a n θ 2 0 ] , I 2 + A = [ 1 t a n θ 2 − t a n θ 2 1 ] , I 2 − A = [ 1 t a n θ 2 − t a n θ 2 1 ]           

  ( I 2 + A ) ( I 2 − A ) − 1 = [ a − b b a ]          

  a 2 + b 2 = | ( I 2 + A ) ( I 2 − A ) − 1 | = s e c 2 θ 2 * c o s 2 θ 2 = 1          

∴ 1 3 ( a 2 + b 2 ) = 1 3 * 1 = 1 3

New answer posted

a year ago

0 Follower 19 Views

P
Payal Gupta

Contributor-Level 10

8 * 3 * 32 = 24 * 81

Total = n (A) = 93 + 24 * 81 = 81 * 33

In favourable events, the last digit of the number must be either 2 or 7.

Favourable cases = 8 * 9 2 + 9 2 + 8 * 9 * 2 = 8 7 3 , probability = 8 7 3 8 1 * 3 3 = 9 7 2 9 7

New answer posted

a year ago

0 Follower 3 Views

A
alok kumar singh

Contributor-Level 10

Critical point of function are x = − 1 2 , 1 and -2 but x = -2 is making zero .


∴ n o n     d i f f e r e n t i a b l e     a t     x = − 1 2 , 1      

New answer posted

a year ago

0 Follower 3 Views

V
Vishal Baghel

Contributor-Level 10

Δ E = h v → ( 1 n 2 2 − 1 n 1 2 )

(1) n1 = 3, n2 = 2

    ( 1 2 2 − 1 3 2 ) = 9 − 4 3 6 = 5 3 6         

(2) n1 = 4, n2 = 3

( 1 3 2 − 1 4 2 ) = 1 6 − 9 1 4 4 = 7 1 4 4        

(3) n1 = 2, n2 = 1

( 1 1 2 − 1 2 2 ) = 4 − 1 4 = 3 4  

(4) n1 = 5, n2 = 4

( 1 4 2 − 1 5 2 ) = 2 5 − 1 6 4 0 0 = 9 4 0 0

New answer posted

a year ago

0 Follower 6 Views

V
Vishal Baghel

Contributor-Level 10

F n e t = 2 k e e ( d 2 + x 2 ) s i n θ = ( 2 k e 2 ( d 2 + 2 ) ) θ

[for small displacement i.e, x is small so|, sin ≈ ≈   tan ]

= 2 k e 2 ( d 2 + x 2 ) . x d = 2 . 1 4 π ε 0 q 2 x d 3   [q = e]

= q 2 2 π ε 0 d 3 x = m ω 2 x

∴ ω = q 2 2 π ε 0 d 3 m

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