Related InterviewSolutions

• A metallic surface ejects electrons when hit by green light but none when hit by yellow light . Will the electrons be ejected if the same surface is hit by red lightA. yesB. noC. yes, if the red beam is sufficiently intenseD. yes , if the red beam is allowed to fall for sufficient duration
• An electron of velocity `2.652 xx 10^(7)` m/s enters a uniform magnetic field of direction of motion . The radius of its path isA. 5.3 mmB. 3.5 mmC. 0.3 mmD. 3.0 mm
• Speed of an electron passing undeviated through a region of cross electric and magnetic fields of magnitude `4 xx 10^(5)` V/m and `0.02 Wb//m^(2)` respectively in meter per second isA. `2 xx 10^(6)`B. `8 xx 10^(7)`C. `8 xx 10^(6)`D. `2 xx 10^(7)`
• An electron performs uniform circular motion in a region of magnetic field of induction `3 xx 10^(-3) Wb//m^(2)` . If the radius of the circular path of the electron is 2 cm , then the momentum of the electron will beA. `9.6 xx 10^(-24) ` kg m/sB. `6.9 xx 10^(-24)` kg m/sC. `9.6 xx 10^(24)` kg m/sD. `6.9 xx 10^(7)` kg m/s
• The threshold wavelength for tungsten is 2730 Å . The work function of tungsten isA. `4.5 `eVB. 5.4 eVC. 5.0 eVD. 4.0 eV
• A `5 W` source emits monochromatic light of wavelength `5000 Å`. When placed `0.5 m` away , it liberates photoelectrons from a photosensitive metallic surface . When the source is moved to a distance of `1.0 m` the number of photoelectrons liberated will be reduced by a factor ofA. 4B. 8C. 16D. 2
• If a charge particle of charge q , mass m , moves in a circular path in magnetic field of induction B , under a potential of V volts then radius of circular path isA. `sqrt((2 mV)/(q))`B. `(B)/(1) sqrt((2mV)/(q))`C. `(1)/(B) sqrt((2 m V)/(q))`D. `(1)/(B^(2)) sqrt((2mV)/(q))`
• Light of frequency `1.5` times the threshold frequency is incident on a photo-sensitive material. If the frequency is halved and the intensity is doubled, the photoelectric current becomesA. quadrupledB. doubledC. halvedD. zero
• A certain spectral line has wavelength of `4000 Å`. Calculate the frequency and the energy in electron volts of the photons associated with it.
• The ratio of energy of photon of a wavelength `10^(-10)` m that of photon of wavelength `5 xx 10^(-8)` m isA. `50 : 1`B. ` 200 : 1`C. `500 : 1`D. `100 : 1`