Class 12 Dual Nature Of Radiation And Matter CBSE Questions & Answers

If the energy of a photon corresponding to a wave length of 6000 \(\mathop A\limits^0 \) is 3.32 \( \times {\rm{ 1}}{0^{{\rm{19}}}}\) joule, the photon energy for a wavelength of 4000 \(\mathop A\limits^0 \) will be

The work function for aluminium surface is 4.2 eV. The cutoff wavelength for the photo electric effect for the surface is

The work function of a photoelectric material is 3.32 eV. The threshold frequency will be equal to

Light of wavelength 4000 \(\mathop A\limits^0 \) is incident on a metal plate whose work function is 2 eV. The maximum kinetic energy of the emitted photoelectrons would be

Given h = 6.6 \( \times {\rm{1}}{0^{ - {\rm{34}}}}\) joule sec, the momentum of each photon in a given radiation is 3.3 \( \times {\rm{1}}{0^{ - {\rm{29}}}}\) kg metre/sec. The frequency of radiation is

In a Milikan’s oil drop apparatus an oil drop of radius 6 \( \times {\rm{1}}{0^{ - {\rm{5}}}}\) m and of density 0.85 \( \times {\rm{1}}{0^{ - {\rm{5}}}}\) kg/m3 is seen to fall freely (without any field). The velocity of drop, given viscosity of air to be 1.83\( \times {\rm{1}}{0^{ - {\rm{5}}}}\) \({\rm{N}} - {\rm{s}}/{{\rm{m}}^{\rm{2}}}\) and neglecting the effect of up thrust force due to air, is

If the wavelength of light falling on a surface is increased from 3000 \(\mathop A\limits^0 \) to 3040 \(\mathop A\limits^0 \), then what will be the corresponding change in the stopping potential (given that hc = 12.4\( \times {\rm{1}}{0^{\rm{7}}}\) eVÅ)?

If the wavelength of light incident on photo-electric cell be reduced from 4000\(\mathop A\limits^0 \) to3600\(\mathop A\limits^0 \),then what will be the change in the cut off potential. {tex}\left( {{\rm{h }} = {\rm{ 6}}.{\rm{6 }} \times {\rm{1}}{0^{ - {\rm{34}}}}{\rm{J }}-{\rm{ s}},{\rm{ c }} = {\rm{ 3}}.0{\rm{ }} \times {\rm{1}}{0^{\rm{8}}}{\rm{m}}/{\rm{s}},{\rm{ e }} = {\rm{ 1}}.{\rm{6 }} \times {\rm{ 1}}{0^{ - {\rm{19}}}}{\rm{C}}} \right){tex}

If the voltage across the electrodes of a cathode ray tube is 500 volts then energy gained by the electrons is

If an electron is accelerated by 8.8\( \times {\rm{1}}{0^{{\rm{14}}}}{\rm{m}}/{{\rm{s}}^{\rm{2}}}\)then electric field required for acceleration is (given specific charge of the electron = 1.76\( \times {\rm{1}}{0^{{\rm{11}}}}{\rm{Ck}}{{\rm{g}}^{ - {\rm{1}}}}\))

If a beam goes undeflected in Thomson’s experiment, then speed of the electron is (given E = 30 V \({\rm{c}}{{\rm{m}}^{ - {\rm{1}}}}\) and B = 6.06 T)

When an electron enters a magnetic field of 0.01 T with a speed of \({\rm{1}}{0^{\rm{7}}}{\rm{m }}{{\rm{s}}^{ - {\rm{1}}}}\) it describes a circle of radius 6 mm there. Then specific charge of the electron is given by

1.If an electron moving with a speed of 2.5\( \times {\rm{1}}{0^{\rm{7}}}{\rm{m }}{{\rm{s}}^{ - {\rm{1}}}}\) is deflected by an electric field of 1.6 k V \({{\rm{m}}^{ - {\rm{1}}}}\)perpendicular to its circular path, then e/m for the electron will be (given radius of circlar path = 2.3 m)

If an electron accelerated through a potential difference of 500 volt attains a speed of 1.33 \( \times {\rm{1}}{0^{\rm{7}}}{\rm{m }}{{\rm{s}}^{ - {\rm{1}}}}\) then specific charge of the electron should be

If an electron accelerated from rest through a potential of 200 V acquires a speed of 84\( \times {\rm{1}}{0^{{\rm{16}}}}{\rm{m }}{{\rm{s}}^{ - {\rm{1}}}}\), then its e/m is