Quiz for the JUAS 2025 students – Electromagnetism

Applying the Stokes theorem, the two Faraday and Ampere-Maxwell law local form are (select both correct answers):

The skin depth is:

Applying the Gauss-Ostrogradski theorem, the two Gauss laws in local forms are (select both correct answers):

In particle accelerators, the resonant cavities are used to:

Can the phase velocity , the velocity of the wave-front in the waveguide, be larger than the speed of light c?

How are the cavities fed?

The Gauss law for the magnetic induction demonstrates that the flux of the magnetic induction through the volume surface is equal to:

The Ampere Law states that the circulation of the magnetic field along a closed path equals the flux of current through any open surface confined by the closed path. Maxwell added a term to balance the equations that is:

By applying the phasor definition, the time derivative is replaced by the factor

For the plane waves, there are two solutions representing two waves, they are:

What is the order of magnitude of the quality factor Q in the superconducting Niobium cavities?

What is the velocity of the electromagnetic waves in vacuum?

The charge conservation principle states that the flux of current density through a closed surface is equal to:

The Gauss law states that, given an arbitrary distribution of charge density inside the volume, the total amount of charge inside this volume is equal to

In case of rectangular waveguides, how are the modes classified?

The Faraday law states that the time variation of the magnetic induction flux through any open surface confined by a closed path is equal to:

In many applications of the coaxial cable, how much is the characteristic impedance?

What happens below the cut-off frequency in a waveguide?