Electromagnetic Fields and Waves MCQs (Part-9)

What is the primary role of electromagnetic compatibility (EMC) in electrical systems?

A Increase power
B Prevent noise
C Enhance frequency
D Reduce heat

The skin effect causes current to flow more near which part of the conductor?

A Core
B Center
C Surface
D Inside

What does the Poynting vector represent in an electromagnetic field?

A Power flow
B Electric field direction
C Energy loss
D Magnetic field direction

What is the main source of electromagnetic interference (EMI)?

A Magnetic field
B Voltage drop
C Electric charge
D Electric current

What is the effect of an increase in the frequency on the skin depth of a conductor?

A Increase
B No effect
C Decrease
D Depends on material

In electromagnetic waves, what is the relationship between the electric and magnetic fields?

A Perpendicular
B Parallel
C In phase
D Out of phase

What does electromagnetic compatibility (EMC) ensure in communication systems?

A Faster communication
B Reduced interference
C Signal clarity
D Signal reflection

How does the Poynting vector relate to the energy flow in an electromagnetic field?

A Direction of wave propagation
B Strength of electric field
C Energy absorption rate
D Energy transfer direction

The skin effect increases the resistance of conductors at which frequencies?

A Low frequencies
B Medium frequencies
C High frequencies
D Zero frequencies

What is the primary role of shielding in electromagnetic systems?

A Block interference
B Increase voltage
C Enhance power
D Reflect waves

What does a high Poynting vector magnitude indicate?

A Low energy transfer
B Magnetic field strength
C High energy flow
D Low voltage

What type of material is used for shielding against electromagnetic interference (EMI)?

A Insulators
B Conductors
C Dielectrics
D Semiconductors

What effect does the skin effect have on the distribution of current in a conductor?

A Even current distribution
B Current in center
C Current uniform throughout
D Current concentrated at surface

What does a low Poynting vector indicate in an electromagnetic wave?

A High power flow
B High interference
C Low energy flow
D Low wavelength

What is the primary cause of electromagnetic interference (EMI) in power lines?

A Rapid current changes
B High frequency oscillations
C Electromagnetic wave reflection
D Low voltage fluctuations