An atom emits energy equal to `4 xx 10^(-12)` erg. In which part of the electromagnetic spectrum does the corresponding line lie?

Correct Answer - C `lambda=(C)/(v)=( 3 xx 10^(8))/( 6 xx 10^(12))=5 xx 10^(-5)` `:. lambda = 500 xx 10^(-7) m ` i.e. `lambda gt lambda_R ` `:. ` This lies in...

Correct Answer - B `n^(th)` excited state `=.^(n+1)C_(2) =(n(n+1))/(2) =Sigma n`

Correct Answer - A Radio waves have maximum wavelength in the range of `0.1 m` to `10^(-4) m`.

Correct Answer - A`to` r,s ; B`to`p,s ; C`to`q,r,s ; D`to` p,q,s,t (A)`6to3 " " Deltan=3` `:.` no of lines `=(3(3+1))/2=6` All lines are in infrared region (B)`7to3 " " Deltan=4`...

Correct Answer - B Frequency, `upsilon=(omega)/(2pi)=(5.4xx10^(8)xx7)/(2xx22)` `=8.6xx10^(7)Hz`

Correct Answer - D Microwaves are used to cook food. Microwave oven is a domestic application of these waves.

Correct Answer - B Consider a plane perpendicular to the direction of propagation of the electromagnetic wave. If electric charges are present in this plane, they will be set and sustained...

Correct Answer - A Electromagnetic waves have linear momentum as well as energy. This concludes that they can exert radiation pressure by falling beam of electromagnetic radiation on an object.

Correct Answer - D `(1)/(lambda)=R[1/(2^2)-1/(5^2)]=R[1/(4)-1/(25)]=(21R)/(100)` `therefore lambda=(100)/(21R)=(100)/(21xx1.1xx10^7)=(100)/(23.1)xx10^-7m=4346Å` This corresponds to voilet.

Correct Answer - C According to classical electronmagnetic theory, an accelerated charge continuously emits radiation. As electrons revolving in circular paths are constantly experiencing centripetal acceleration,hence thay will be losing their...