Maxwell's Equation MCQ Level - 2 - Physics MCQ

As the capacitor is being discharged, field is decreasing

Using expression for curl in cylindrical coordinates, we get

Since there is φ symmetry

Thus, magnetic field in  direction will be induced, since,
∴ Direction of poynting vector 

 radially outward

The correct answer is: Radially outward 

The induced electric field lines are concentric circles with clockwise direction.
Physical argument for the direction is that if we put a conducting loop in the magnetic field current will flow in clockwise direction.
∴  Along a circle of radius r, we get

Here  means  is in each a direction to oppose change in flux.
The correct answer is:  

Let us take a loop of radius x with centre on the axis 
Current enclosed

Applying Maxwell’s equation

The correct answer is: 

Electric flux is zero. It may happen for E ⊥ ds.

Potential difference is zero.
E is not necessarily zero.

⇒ E is produced, if magnetic flux changes with time. Thus, no equation gives E as zero.

The correct answer is: None of these

Let us use the equation

 (After integration)

The correct answer is:  

Gauss’s law in magnetostatics states that the surface integration of magnetic fields over a closed surface is zero. Its differential form is: div B = 0.

Ex and By would generate a plane electromagnetic wave travelling in z-direction. E, B and k form a right handed system where k is along z-axis. (As, i x j = k) ∴ E is along x-axis and B is along y-axis

Power = 2 kW = 2 × 10³ W
Cross-sectional area = 10⁶ cm²
Poynting vector S = P/A

The correct answer is: 2 × 10¹³ W/m²

Lorentz force is the force on a particle when it moves through a medium where both magnetic and electric fields are present.