EMF UT 2 (SECTION-I)

Which of the following statements are incorrect?

• Displacement current exists inside perfect solid conductor

• Displacement current exists inside a perfect sheet of conductor

• Current density and current are directly proportional

• Current density and current are indirectly proportional

Which of the following is not described in Faraday's experiment?

• Change in magnetic flux linkage

• Electromotive force

• Static Electric field

• Number of turns in a closed circuit

The concept of displacement current was a major contribution attributed to

• Faraday

• Gauss

• Ampere

• Maxwell

Which one of the following is correct?Which one of the following is correct?

• Pointing vector is a power density vector.

• Faraday discovered conduction current density

• Ampere discovered Electromagnetic induction

• Gauss law relates curl of magnetic field

According to Amperes law

• Total electric flux is equal to electric charge

• Total magnetic flux is equal to electric charge

• Total magnetic flux is equal to total current

• Total electric flux is equal to total current

In free space Electric field  E is E= $20\cos⁡(10^{12}t-50x)(a_y)⃗V/m$  Its  magnetic field is?

•  $H⃗=10.62\cos⁡(10^{12}t-50x)(a_z)⃗A/m$  

•  $H⃗=1.77\cos⁡(10^{12}t-50x)(a_z)⃗A/m$  

•  $H⃗=3.54\cos⁡(10^{12}t-50x)(a_z)⃗A/m$  

•  $H⃗=21.2\cos⁡(10^{12}t-50x)(a_z)⃗A/m$  

A material has a conductivity of 0.01mho/m and a relative permittivity of 4. The frequency at which conduction current in the medium is equal to the displacement current is, (Gate 2001)

• 400 MHz.

• 90 MHz.

• 45 MHz.

• 900 MHz

In an Electromagnetic wave the Electric field lies along X direction and the wave is propagating along Y direction, then the direction of Magnetic field is,

• Along positive Z direction

• Along negative X direction

• Along positive X direction

• Along negative Z direction

Which of the following represents continuity of current?

• $∇.H⃗=0$

• $∇.J⃗=-(∂ρ_v)/∂t$

• $∇×E⃗=-(∂B⃗)/∂t$

• $∇×H⃗=I$

Inconsistency in the Ampere's circuit law for time varying fields is eliminated by introducing.

• Conduction current density

• Transformer e.m.f.

• A combination of motional & transformer e.m.f.

• None of these