List of top Physics Questions on Wave characteristics asked in JEE Main

The work function of a substance is 3.0 eV. The longest wavelength of light that can cause the emission of photoelectrons from this substance is approximately:
In single electron \(atom/ion\), first member of Lyman series is \(λ\), then wavelength of second member of their series shall be
Stopping potential is \(8\) \(V\) if wavelength of incident light is \(λ\) and it is \(2\) \(V\) for \(3λ\). Find threshold wavelength.

In an amplitude modulation, a modulating signal having amplitude of \(X V\) is superimposed with a carrier signal of amplitude \(Y V\) in first case. Then, in second case, the same modulating signal is superimposed with different carrier signal of amplitude \(2 YV\). The ratio of modulation index in the two cases respectively will be :

Amplitude modulated wave is represented by VAM = 10[1+0.4cos(2π×104t] cos(2π×107t). The total bandwidth of the amplitude modulated wave is:
Choose the correct statement for amplitude modulation :
An antenna is placed in a dielectric medium of dielectric constant \(6.25\). If the maximum size of that antenna is \(5.0\) \(mm\), it can radiate a signal of minimum frequency of __________GHz. (Given \(μr\) = \(1\) for dielectric medium)
If a wave gets refracted into a denser medium, then which of the following is true?
We do not transmit low frequency signal to long distance because-
(a) The size of the antenna should be comparable to signal wavelength which is unreal solution for a signal of longer wavelength
(b) Effective power radiated by a long wavelength baseband signal would be high
(c) We want to avoid mixing up signals transmitted by different transmitter simultaneously
(d) Low frequency signal can be sent to long distances by superimposing with a high frequency wave as well
Therefore, the most suitable option will be