Dual Nature of Radiation and Matter

An electron of mass 'm' with an initial velocity v=v0 i (v0>0) enters an electric field E=-Eo k. If the initial de Broglie wavelength is 0, the value after time t would be

1. o 1- e2Eo2t2m2vo2
2. 0
3. o 1+ e2Eo2t2m2vo2
4. o 1+ e2Eo2t2m2vo2

In photoelectric effect, the stopping potential (V0) v/s frequency ( ) curve is plotted. ( h is the Planck's constant and 0 is work function of metal ) Choose the correct answer from the options given below :

1. (A), (C) and (E) only
2. (C) and (D) only
3. (A), (B) and (C) only
4. (D) and (E) only

The ratio of the power of a light source S1 to that of the light source S2 is 2. S1 is emitting 2 1015 photons per second at 600 nm. If the wavelength of the source S2 is 300 nm, then the number of photons per second emitted by S2 is 1014.

A sub-atomic particle of mass 10-30 kg is moving with a velocity 2.21 106 m/s. Under the matter wave consideration, the particle will behave closely like (h=6.63 10-34 J.s )

1. X-rays
2. Infra-red radiation
3. Gamma rays
4. Visible radiation

In photoelectric effect an em-wave is incident on a metal surface and electrons are ejected from the surface. If the work function of the metal is 2.14 eV and stopping potential is 2 V, what is the wavelength of the em-wave? (Given hc=1242 eV nm where h is the Planck's constant and c is the speed of light in vacuum.)

1. 400 nm
2. 600 nm
3. 300 nm
4. 200 nm

The work functions of cesium (Cs) and lithium (Li) metals are 1.9 eV and 2.5 eV , respectively. If we incident a light of wavelength 550 nm on these two metal surfaces, then photo-electric effect is possible for the case of

1. Both Cs and Li
2. Neither Cs nor Li
3. Li only
4. Cs only

A light source of wavelength illuminates a metal surface and electrons are ejected with maximum kinetic energy of 2 eV . If the same surface is illuminated by a light source of wavelength 2, then the maximum kinetic energy of ejected electrons will be (The work function of metal is 1 eV )

1. 5 eV
2. 3 eV
3. 2 eV
4. 6 eV

A proton, an electron and an alpha particle have the same energies. Their de-Broglie wavelengths will be compared as :

1. p > e >
2. < p < e
3. e > > p
4. p < e <

UV light of 4.13 eV is incident on a photosensitive metal surface having work function 3.13 eV. The maximum kinetic energy of ejected photoelectrons will be:

1. 4.13 eV
2. 1 eV
3. 7.26 eV
4. 3.13 eV

A proton and an electron are associated with same de-Broglie wavelength. The ratio of their kinetic energies is: (Assume h = 6.63 10-34 J s, me = 9.0 10-31 kg and mp = 1836 times me)

1. 1 : 11836
2. 1 : 1836
3. 1 : 1836
4. 1 : 1 1836