A laser beam of wavelength `lambda_(1) = 5 xx 10^(– 7) m` strikes normally a blackened plate and produces a force of `10^(– 5) N`. Mass of the plate is `10 g` and its specific heat capacity is `400 J kg^(–1) K^(–1)`. At what rate will the temperature of the plate rise? Assume no heat loss to the surrounding.
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Cut off potential for a metal in photoclectric effect for light of wavelength `lambda_(1), lambda_(2)` and `lambda_(3)` is found to be `V_(1),V_(2)` a
Correct Answer - C `eV_(1)=(hc)/lambda_(1) - phi, eV_(2)=(hc)/lambda_(2) - phi, eV_(3)=h_(0)/lambda_(3)-phi` if `2V_(2)=V_(1)+V_(3) implies 2/lambda_(2)=1/lambda_(1)+1/lambda_(2)` harmonic progression
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The equivalent conductances of NACl at concentration c and at infinite dilution are `lambda_(c)` and `lambda_(oo)` respectively. The correct relations
Correct Answer - A According to Debye-Huckel relation : `lambda_(c)=lambda_(oo)-b sqrt(c)`
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The wavelength of electron waves in two orbits `(lambda_(1) : lambda_(2))`
Correct Answer - A `lambda=(h)/(sqrt(2mKE)), (lambda_(1))/(lambda_(2))=sqrt((KE_(2))/(KE_(1))), (3)/(5)=sqrt((KE_(2))/(KE_(1))),(KE_(1))/(KE_(2))=(25)/(9)`
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Show that if `lambda_(1), lambda_(2), ...., lamnda_(n)` are `n` eigenvalues of a square matrix a of order n, then the eigenvalues of the matric `A^(2)
`AX=lambdaX` or `A(AX)=A(lambdaX)` or `A^(2)X=lambda(AX)=lambda(lambdaX)=lambda^(2)X` i.e., `A^(2)X=lambda^(2)X` Hence, eigenvalue of `A^(2)` is `lambda^(2)`. Thus, if `lambda_(1), lambda_(2), ..., lambda_(n)` are eigenvalue of A, then `lambda_(1)^(2), lambda_(2)^(2), ..., lambda_(n)^(2)` are eigenvalues...
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A `0.6 xx 10^(-3) W` laser is aimed at the Moon. The wavelength of emitted light is 600 nm and the laser beam spreads out of the source at a divergenc
Correct Answer - `5.7 xx 10^(4) m^(-2) s^(-1)`
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When radiations of wavelength `lambda_(1), lambda_(2) (= 0.6 lambda_(1)), lambda_(3) (= 4lambda_(2))` and `lambda_(4)` are incident on a metal plate,
Correct Answer - (a) `5 eV` , (b) `n = 6, Z = 3`
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A radioactive nucleus A decays into B with a decay constnat `lambda_(1)`. B is alos radioactive and it decays into C with a decay constant of `lambda_
Correct Answer - (a)`(dN_(2))/(dt)=-lambda_(2)N_(2)+lambda_(1)N_(1)^(0)e^(-lambda_(1)t)` (b) `(A_(2))/(A_(1))=(lambda_(2))/(lambda_(2)-lambda_(1))` (c) `((1)/(lambda_(2)-lambda_(1)))ln((lambda_(2))/(lambda_(1)))`
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(a) If the wavelength of the light incident on a photoelectric cell be reduced from `lambda_(1)` to `lambda_(2) Å`, then what will be the change in th
Correct Answer - 2.3 eV, `1.44 xx 10^(-6)` Vm
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A laser beam has a wavelength of `6xx10^(-7)`m and aperture of `6xx10^(-2)`m. The beam is sent towards the moon which is at a distance of `4xx10^(8)`m
Correct Answer - (i)`1.22xx10^(-5)rad(ii) 2.381xx10^(7)`m
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A laser beam has a power of 100 mW. It has an aperture of `5xx10^(-3)`m and emits a wavelength 6943 Å. The beam is focused with a lens of focal length
Correct Answer - `2.87xx10^(-10)m^(2),3.48xx10^(8)Wm^(-2)`
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