de Broglie proposed dual nature for electron by putting his famous equation `lambda = (h)/(mv).` Later on, Heisenberg proposed uncertainty principle a

Monjur Alahi

de Broglie proposed dual nature for electron by putting his famous equation `lambda = (h)/(mv).` Later on, Heisenberg proposed uncertainty principle as `deltapDeltax ge (h)/(4pi).` On the contrary,
Particle nature of electron was established on the basis of photoelectric effect. When a photon strikes the metal surface it gives up its energy to the electron. Part of this energy (say W) is used by the electrons to escape from the metal and the remaining energy imparts kinetic energy `(1//2 mv^(2))` to the ejected photoelectron. The potential applied on the surface to reduce the velocity of photoelectron to zero is known as stopping potential .
The circumference of third orbit of a single electron species is 3 nm. What may be the approximate wavelength of the photon required to just ionize electron from this orbit?
A. `19.2xx10^(-2) m`
B. `5.76xx10^(-2) m`
C. `3.84xx10^(-2) m`
D. `1.92xx10^(-2) m`


0 like 0 dislike
2 views
Share with your friends

1 Answers

Salim Ahmed Kawsar

Call

Correct Answer - D
`Deltax=(h)/(4pi Me)xx1/(DeltaV)" "DeltaV=V 0.001/100=300xx10^(-5) m//s`
`Deltax=5.8xx10^(-5)xx1/(300xx10^(-5))=1.92xx10^(-2) m`

0 like 0 dislike
1 views
Talk Doctor Online in Bissoy App
The French physical Louis de Broglie in 1924 postulated that matter, like radiation, should exhibit a dual behaviour. He proposed the following relati

Correct Answer - C `lambda=h/(mv)=(6.6xx10^(-34))/(9.1xx10^(-31)xx3xx10^6)=242` pm

2 Answers 1 views
The de Broglie wavelength of an electron moving in a circular orbit is `lambda` . The minimum radius of orbit is :

Correct Answer - B We know `2 pir=nlambda` For minimum radius `n=1` `2pir_("min")=lambda` `r_("min")=lambda/(2pi)`

2 Answers 1 views
Uncertainty in position of a hypothetical subatomic particle is `1 "Å"` and uncertainty in velocity is `(3.3)/(4 pi) xx 10^(5)` m/s then the mass of t

Correct Answer - C `Deltax xx m xx Deltav ge h//4pi` `1 xx10^(-10)xxmxx3.3/(4pi)xx10^(5) ge (6.6xx10^(-34))/(4xxpi) m=2xx10^(-29) kg`

2 Answers 1 views
Calculate the uncertainty in velocity of an electron. If the uncertainty in its position `10^(-13)c.m.` `(h=6.6xx10^(-34)J,m=9.1 xx 10^(-31)kg)`

Correct Answer - A `A(g)+e^(-)rarrA^(-)(g)" "DeltaH=-a(E.G.E.)` `A^(-)(g)rarrA(g) +e^(-)" "DeltaH=+b(l.E)`

2 Answers 1 views
If uncertainty in momentum is twice the uncertainty in position of an electron then uncertainty in velocity is `(h=(h)/(2pi))` :

Correct Answer - A Frequency `(f) alpha z ^(2)//n^(3)implies(f_(1))_(H)//(f_(3))_(He^(+))=(1s^(2)//1^(3))//(2^(2)//3^(3))=27//4`

2 Answers 1 views
If `[(lambda^(2)-2lambda+1,lambda-2),(1-lambda^(2)+3lambda,1-lambda^(2))]=Alambda^(2)+Blambda+C`, where A, B and C are matrices then find matrices B a

We have `[(lambda^(2)-2lambda+1,lambda-2),(1-lambda^(2)+3lambda,1-lambda^(2))]=Alambda^(2)+Blambda+C` Putting `lambda=0`, we get `C=[(1,-2),(1,1)]` Putting `lambda=1`, we get `A+B+C=[(0, -1),(3,0)]` ...(1) Putting `lambda=-1`, we get `A-B+C=[(4,-3),(-3,0)]` Subtracting (2) from (1), we get `2B[(0, -1),(3,0)]-[(4,-3),(-3,0)]=[(-4,2),(6,0)]` `:. B=[(-2,...

2 Answers 1 views
Find the value of `lambda` if the equation `(x-1)^2+(y-2)^2=lambda(x+y+3)^2` represents a parabola. Also, find its focus, the equation of its directri

We have equation `(x-1)^(2)+(y-2)^(2)=lamda(x+y+3)^(2)` `orsqrt((x-1)^(2)+(y-2)^(2))=sqrt(2lamda)(|x+y+3|)/(sqrt(1^(2)+1^(2)))` This represents parabola if `sqrt(2lamda)=1` `:." "lamda=(1)/(2)` Focus of the parabola is S (1,2) and directrix is x+y+3=0. Axis passes through focus and it is...

2 Answers 4 views
The circumference of circular orbit of electron in a `He^(+)` ion is five times the de-Broglie wavelength associated with the electron. Find the radiu

Correct Answer - `6.613 Å`

2 Answers 3 views
If the equations `4x^(2)-x-1=0` and `3x^(2)+(lambda+mu)x+lambda-mu=0` have a root common, then the rational values of `lambda` and `mu` are

Correct Answer - C `(c )` Roots of `4x^(2)-x-1=0` are irrational. So, one root common implies both roots are common. `:. (4)/(3)=(-1)/(lambda+mu)=(-1)/(lambda-mu)=(-2)/(2lambda)=(0)/(2mu)` So, `lambda=(-3)/(4)`, `mu=0`

2 Answers 1 views
Find all values of `lambda` for which the `(lambda-1)x+(3lambda+1)y+2lambdaz=0(lambda-1)x+(4lambda-2)y+(lambda+3)z=0 2x+(3lambda+1)y+3(lambda-1)z=0` p

Correct Answer - D `(d)` `|{:(lambda-1,3lamda+1,2lambda),(lambda-1,4lambda-2,lambda+3),(2,3lambda+1,3(lambda-1)):}|=0` `implieslambda=0` or `3` If `lambda=0`, the equations become `-x+y=0`, `-x-2y+3z=0` and `2x+y-3z=0`, `:. (x)/(6-3)=(y)/(6-3)=(z)/(-1+4)`

2 Answers 1 views
X