Consider a closed surface S surrounding volume V. If is the position vector
of a point inside S, with the unit normal on S, the value of the integral is

**A. ** 3V

**B. ** 5V

**C. ** 10V

**D. ** 15V

**Answer : ****Option D**

**Explaination / Solution: **

From Divergence theorem, we have

From Divergence theorem, we have

The position vector

Here, , thus

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A current sheet lies on the dielectric interface x = 0
between two dielectric media with ε_{r1} = 5, μ_{r1} = 1 in Region -1 (x < 0) and εr2 = 5, μr2 = 2 in Region -2(x > 0) . If the magnetic field in Region-1 at
x = 0^{-} is the magnetic field in Region-2 at x = 0^{+} is

**A. **

**B. **

**C. **

**D. **

**Answer : ****Option A**

**Explaination / Solution: **

From boundary condition

From boundary condition

Then from Boundary condition

Comparing we get A = 30 and B =- 10

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A dielectric slab with 500mm x 500mm cross-section is 0.4m long. The slab is
subjected to a uniform electric field of . The relative
permittivity of the dielectric material is equal to 2. The value of constant ε_{0} is 8.85 × 10^{-12} F/m. The energy stored in the dielectric in Joules is

**A. ** 8.85 × 10-11

**B. ** 8.85 × 10-5

**C. ** 88.5

**D. ** 885

**Answer : ****Option B**

**Explaination / Solution: **

No Explaination.

No Explaination.

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The electric field component of a time harmonic plane EM wave traveling in a nonmagnetic lossless dielectric medium has an amplitude of 1 V/m. If the relative permittivity of the medium is 4, the magnitude of the time-average power density vector (in W/m^{2}) is

Intrinsic impedance of EM wave

Time average power density

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The electric and magnetic fields for a TEM wave of frequency 14 GHz in a
homogeneous medium of relative permittivity ε_{r} and relative permeability

**A. ** εr = 3, Ep= 120π
**B. ** εr = 3, Ep= 360π

**C. ** εr = 9, Ep= 360π

**D. ** εr = 9, Ep= 120π

**Answer : ****Option D**

**Explaination / Solution: **

From the expressions of we can write,

Assuming the speed of light in free space to be 3 × 10^{8} m/s, the intrinsic
impedance of free space to be 120π, the relative permittivity εr of the medium
and the electric field amplitude Ep are

From the expressions of we can write,

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Two infinitely long wires carrying current are as shown in the figure below. One wire is in the y - z plane and parallel to the y axis. The other wire is in the x - y plane and parallel to the x - axis. Which components of the resultingmagnetic field are non-zero at the origin ?

**A. ** x,y,z components

**B. ** x,y components

**C. ** y, z components

**D. ** x,z components

**Answer : ****Option D**

**Explaination / Solution: **

Due to 1 A current wire in x - y plane, magnetic field be at origin will be in x direction.

Due to 1 A current wire in y - z plane, magnetic field be at origin will be in z direction.

Thus x and z component is non-zero at origin.

Due to 1 A current wire in x - y plane, magnetic field be at origin will be in x direction.

Due to 1 A current wire in y - z plane, magnetic field be at origin will be in z direction.

Thus x and z component is non-zero at origin.

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If a vector field is related to another vector field through which of the following is true? (Note : C and SC refer to any closed contour and any surface whose boundary is C . )

**A. **

**B. **

**C. **

**D. **

**Answer : ****Option B**

**Explaination / Solution: **

Hence (B) is correct option.

Hence (B) is correct option.

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A plane wave having the electric field components V/m and traveling in free space is incident normally on a lossless medium with which occupies the region y ≥ 0. The reflected magnetic field component is given by
**A. **

**B. **

**C. **

**D. **

**Answer : ****Option A**

**Explaination / Solution: **

In the given problem

In the given problem

Reflection coefficient

negative So magnetic field component does not change its direction Direction of incident magnetic field

So, reflection magnetic field component

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The silicon sample with unit cross-sectional area shown below is in thermal equilibrium. The following information is given: T = 300 K electronic charge = 1.6 × 10^{-19} C, thermal voltage = 26 mV and electron mobility = 1350 cm^{2} / V-s

The magnitude of the electric field at x = 0.5 μm is

No Explaination.

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The silicon sample with unit cross-sectional area shown below is in thermal equilibrium. The following information is given: T = 300 K electronic charge = 1.6 × 10^{-19} C, thermal voltage = 26 mV and electron mobility = 1350 cm^{2} / V-s

The magnitude of the electron of the electron drift current density at x = 0.5 μm is

Electron drift current density

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**Preparation Study Material**- Circuit Theory (Study/Preparation)
- Electromagnetic Theory (Study/Preparation)
- Digital Logic Circuits (Study/Preparation)
- Signals and Systems (Study/Preparation)
- Electrical Machines I (Study/Preparation)
- Electrical Machines II (Study/Preparation)
- Transmission and Distribution (Study/Preparation)
- Power System (Study/Preparation)
- Control Systems (Study/Preparation)
- Digital Logic Circuits (Study/Preparation)
- Electronic Devices and Circuits (Study/Preparation)
- Microprocessors and Microcontrollers (Study/Preparation)
- Power Electronics (Study/Preparation)

- Engineering Mathematics (Practise Test)
- Electric Circuits (Practise Test)
- Electromagnetic Fields (Practise Test)
- Signals and Systems (Practise Test)
- Electrical Machines (Practise Test)
- Power Systems (Practise Test)
- Control Systems (Practise Test)
- Electrical and Electronic Measurements (Practise Test)
- Analog and Digital Electronics (Practise Test)
- Power Electronics (Practise Test)