A star is moving away from an observer with a speed of `500 kms^(-1)` .Calculate the Doppler shift if the wavelength of light emitted by the star is 6000`Å`.
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If a light with frequency `4xx10^(16) Hz` emitted photoelectrons with double the maximum kinetic as are emitted by the light of frequency `2.5xx10^(16
Correct Answer - `1xx10^(16) Hz` For frequency `2.5xx10^(16) Hz, h v=hv_(o)+KE_(max)` `:. h(2.5xx10^(16))=hv_(o)+KE_(max) ...(i)` For frequency `4xx10^(16)` Hz, `h(4xx10^(16))=hv_(o)+2KE_(max) ...(2)` Multiply `eq^(n)` (1) by `2` and substract `eq^(n)` (2) from it....
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Calculate the number of photons emitted by a `100 W` yellow lamp in `1.0 s`. Take the wavelength of yellow light as `560 nm` and assume `100` percent
Correct Answer - 4 The number pf photon is `N=E/(hv)=(PDeltat)/(h(c//lambda))=(lambdaPDeltat)/(hc)` Substitution of the data gives `N=((5.60xx10^(-7)m)xx(100Js^(-1))xx(1.0s))/((6.626xx10^(-36)s)xx(3xx10^(8)ms^(-1)))=2.8xx10^(20)`
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Explain the difference between movement and shift in the supply curve. Mention two reasons for shift in supply curve and the reason for movement along
Movement along the supply curve refers to change in quantity of commodity supplied due to change in price of commodity whereas shift of the supply curve refers to either increase...
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An observer views his own image in a convex mirror of radius of curvature R. If the least distance of distinct vision for the observer is d, calculate
Correct Answer - `(R)/(sqrt(R^(2)+d^(2))+d)`
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A star is at a distance of `50xx10^(12)` km from earth. If the star disappears due to collision with some other star so that its light is extinguished
Correct Answer - `5.3`years
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Calculate the kinetic energy of a photoelectron (in eV) emitted on shining light of wavelength `6.2 xx 10^(-6)m` on a metal surface. The work function
Correct Answer - 0.1 eV
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The energy of photoelectrons emitted from a sensitive plate is 1.56 eV. If its threshold old wavelength is `2500 Å`, calculate the wavelength of incid
Correct Answer - `1379 Å`
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Calculate the de Broglie wavelength associated with the following : (i) electrons moving with a speed of `10^(5)ms^(-1)` (ii) protons moving with a sp
Correct Answer - `0.7278 xx 10^(-8)m` `3.97 xx 10^(-12) m` `0.29 xx 10^(-10) m` `1.807 Å` `0.1690 Å` `0.01276 Å`
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A star is moving towards the earth with a speed of `9.0 xx10^(6) ms^(-1)` . If the wavelength of a particular spectral line emitted by it si 6000 `Å`
Correct Answer - `5820Å`
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An observer is travelling in east with a velocity of 2 m/s and observes that wind is blowing in north with a velocity of 2m/s. If observer doubles his
Correct Answer - `2sqrt(2)m//s` N-W
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