Two metallic plates P(collector) and Q (emitter) are separated by a distance of 0.2 m. These are connected through an 0.2 m. These are connected through an ammeter without any cell. A magnetic field B exists parallel to the plates. Light of wavelengths between 2000 Å and 3000 Å fall of the plate Q whose work function is 2.22 eV. The minimum value of B for which the current registered with ammeter is zero, is

Two metallic plates P(collector) and Q (emitter) are separated by a di

1.	Two metallic plates P(collector) and Q (emitter) are separated by a distance of 0.2 m. These are connected through an 0.2 m. These are connected through an ammeter without any cell. A magnetic field B exists parallel to the plates. Light of wavelengths between 2000 Å and 3000 Å fall of the plate Q whose work function is 2.22 eV. The minimum value of B for which the current registered with ammeter is zero, is
Answer» `3.8 xx10^-5 T` `4.7 xx10^-5 T` `6.7 xx10^-5 T` `8.6 xx10^-5 T` ANSWER :C