Electromagnetics – Multiple Choice Questions (MCQs)

1. 85. The electric field due to an infinite line charge is proportional to:

   • A. 1/r
   • B. 1/r²
   • C. r
   • D. r²

2. 86. The electric flux through any closed surface is equal to the total charge enclosed divided by:

   • A. Permittivity of free space
   • B. Permeability of free space
   • C. Speed of light
   • D. Resistance

3. 87. A scalar potential field has a curl of:

   • A. Zero
   • B. Non-zero
   • C. Constant
   • D. Varying

4. 88. The magnetic field outside a long straight current-carrying wire is proportional to:

   • A. 1/r
   • B. 1/r²
   • C. r
   • D. r²

5. 89. The boundary condition for the normal component of the electric flux density at the interface between two dielectric media is that it is:

   • A. Discontinuous if there is surface charge
   • B. Continuous
   • C. Zero
   • D. Infinite

6. 90. The term 'group velocity' is relevant when considering:

   • A. Phase velocity
   • B. Wave packets
   • C. Standing waves
   • D. Monochromatic waves