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Engineering
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If and be the threshold wavelength and wavelength of incident light, the velocity of photoelectron ejected from the metal surface is :

• Option 1)

• Option 2)

• Option 3)

• Option 4)

As discussed in the concept

Photoelectric Effect -

$\frac{1}{2}mu^{2}= hv-hv_{0}$

- wherein

where

m is the mass of the electron

u is the velocity associated with the ejected electron.

h is plank’s constant.

v is frequency of photon,

v0 is threshold frequency of metal.

$v^{2} = \frac{2hc}{m}\left ( \frac{1}{\lambda } - \frac{1}{\lambda _{0}} \right )$

$v =\sqrt{ \frac{2hc}{m}\left ( \frac{1}{\lambda } - \frac{1}{\lambda _{0}} \right )}$

Hence the correct option is 3

Option 1)

Option 2)

Option 3)

Option 4)

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Engineering
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Chloro compound of Vanadium has only spin magnetic moment of 1.73 BM.  This Vanadium chloride has the formula :

(at. no. of V=23)

• Option 1)

VCl2

• Option 2)

VCl4

• Option 3)

VCl3

• Option 4)

VCl5

As discussed in

Magnetic Quantum Number (m) -

It  gives information about the spatial orientation of the orbital with respect to standard set of co-ordinate axis.

-

The value of magnetic moment is 1.73 BM

$1.73 = \sqrt{n\left ( n+2 \right )}$ where n is the number of unpaired electrons

$3 = n \left ( n+2 \right )$

After calculation n = 1

$V_{23} => 1S^{2},2S^{2},2p^{6},3S^{2},3p^{6},4S^{2},3d^{3}$

To obtain one unpaired electron V should be tetrapositive ion and the formula of its chlorid should be $VCl_{4}$

Option 2 is correct

Option 1)

VCl2

Incorrect option

Option 2)

VCl4

Correct option

Option 3)

VCl3

Incorrect option

Option 4)

VCl5

Incorrect option

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Engineering
91 Views   |

The energy absorbed in the transition of the electron from n=2 to 1 in H-atom will be

• Option 1)

10.2 meV

• Option 2)

3.4 meV

• Option 3)

13.6 meV

• Option 4)

12.75 meV

As we learnt in  Lyman Series spectrum -   Where This lies in Ultraviolet region -     where for Lyman series Z=1 (hydrogen) Rydberg constant, R = Energy absorbed = =        = 10.2 meV Option 1) 10.2 meV Option 2) 3.4 meV Option 3) 13.6 meV Option 4) 12.75 meV
Engineering
94 Views   |

Element with electronic configuration $1s^{2}, 2s^{2}, 2p^{6}, 3s^{2}3p^{6}3d^{10},4s^{2}4p^{6}4d^{10}, 5s^{2}5p^{3}$ belongs to which group of the periodic table?

• Option 1)

3rd

• Option 2)

15th

• Option 3)

7th

• Option 4)

2nd

As we learnt in  Aufbau Principle - In the ground state of the atoms, the orbitals are filled in order of their increasing energies. - wherein    Given configuration: Element of the above configuration belongs in p block and for p block elements, group no = valence electrons...
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