Work function of all metals varies from 2 eV to 4eV. It is 4.2 eV for Aluminum and2eV for Sodium. If these two metals are illuminated by same light, the thresholdfrequency ofAluminum is
A whistle is revolved with high speed in a horizontal circle of radius R. to an observer at the centre of the circle the frequency of the whistle will appear to be:
Nuclear fission experiments show that the neutrons the uranium nuclei into two fragment
of about the same size. This process is accompanied by the emission of several:
The emf of a cell of negligible internal resistance is 2V. It is connected to the series
combination of 𝟐𝛀, 𝟑𝛀 𝐚𝐧𝐝 𝟓𝛀 resistance. The potential difference across 𝟑𝛀 resistance will be
in volt:
The spectrum of a star’s light is measured and the wavelength of one of the lines as thesodium’s line is found
to be 589 nm. The same line has the wavelength of 497 nm whenobserved in the laboratory. This means the
star is
