List of top Nanoelectronics Questions on communication systems

Which of the following statements are correct regarding the electric and magnetic fields at any surface of discontinuity ?
• [A.] The tangential component of \(E\) is continuous at the surface
• [B.] The tangential component of \(H\) is continuous across a surface except at the surface of a perfect conductor
• [C.] The tangential component of \(B\) is continuous at the surface of discontinuity
• [D.] The normal component of \(D\) is continuous if there is no surface charge density Choose the correct answer from the options given below :

Convert the binary number \(1101101\) to hexadecimal. Which of the following options is correct ?

The energy-momentum (E-K) relationship in a crystalline solid is usually obtained by solving :

Which sensor characteristic describes its ability to selectively detect a specific analyte without interference from other substances in the sample ?

When the photoresist coating (during IC fabrication) is exposed to ultraviolet light, the photoresist becomes :

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Time varying electric field produces magnetic fields. Reason (R): Time varying magnetic field produces electric fields. In the light of the above statements, choose the most appropriate answer from the options given below :

Correct sequence of electromagnetic radiation in order of increasing frequency.
• [A.] Microwave
• [B.] Radio wave
• [C.] Visible light
• [D.] X-ray
• [E.] Gamma rays Choose the correct answer from the options given below :

Consider the following statements regarding a plane wave propagating through free space. The direction of field :
• [A.] \(\vec{E}\) is perpendicular to the direction of propagation.
• [B.] \(\vec{H}\) is perpendicular to the direction of propagation.
• [C.] \(\vec{E}\) is perpendicular to the direction of field \(\vec{H}\). Choose the correct answer from the options given below :

Coulomb's law states that the force between two point charges \(Q_1\) and \(Q_2\) is :
• [A.] Along the line joining them.
• [B.] Directly proportional to the product of charges \(Q_1\) and \(Q_2\).
• [C.] Inversely proportional to the distance \(R\) between them.
• [D.] Inversely proportional to the square of distance \(R\) between them. Choose the correct answer from the options given below :

A TEM wave impinges obliquely on a dielectric-dielectric boundary with \(\epsilon_{r1}=2\) and \(\epsilon_{r2}=1\). The angle of incidence for total reflection is :

The electric field of an electromagnetic wave propagating in the positive \(z\)-direction is given by : \[ \vec{E}=\hat{a}_x \sin(\omega t-\beta z)+\hat{a}_y \sin\left(\omega t-\beta z+\frac{\pi}{2}\right) \] The wave is :

Medium 1 has the electrical permittivity \(\epsilon_1=1.5\) farad/m and occupies the region to the left of \(x=0\) plane. Medium 2 has the electrical permittivity \(\epsilon_2=2.5\) farad/m and occupies the region to the right of \(x=0\) plane. If in medium 1 \[ \vec{E}_1=(2u_x-3u_y+1u_z)\ \text{Volt/m} \] then \(\vec{E}_2\) in medium 2 is :

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Net charge within a conductor is always zero. Reason (R): The conductor has a very large number of free electrons. In the light of the above statements, choose the most appropriate answer from the options given below :

As frequency increases, the surface resistance of a metal :

The VSWR can have any value between :

DSB-SC signals are generated using:

A signal \(x(t)\) is given below : \[ x(t)=\left(\frac{3}{2}\right)\cos(190\times10^3\pi t)+5\cos(200\times10^3\pi t)+\left(\frac{1}{2}\right)\cos(210\times10^3\pi t) \] What is the power efficiency in the AM signal?

In amplitude modulation:
(A) The envelope detector operates properly, only if $(1/f_c) \leq RC \leq (1/f_m)$
(B) Vestigial sideband modulation is used in television broadcasting.
(C) Selective fading produces more distortion in SSB-SC systems than in DSB-SC.
(D) Efficiency of a suppressed carrier system is 100%, whereas in AM the maximum efficiency is only 33.3%.
Choose the correct answer from the options given below:

The transmission efficiency of an ordinary AM signal with a modulation percentage of 80% is: