# EBU - Basics of Electromagnetics

MigrationCheck-Basics of Electromagnetics

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What does negative work imply?

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What is the equation for the total amount of work needed to pull $3$ charges $Q3$, $Q2$, $Q1$ into a system, one at a time, from infinity?

Where, $V_{ab}=$Potential difference between $Q_{a}$ & $Q_{b}$.
$W_{tot}=$Total work

3 / 162

What is the electrostatic energy density of an air filled capacitor with an electric field $E$ = $12 V/m$?

4 / 162

What is the electrostatic energy in a system with an electric flux density $(D)$ $10\hat{a_{x}} C/m^2$ and electric field intensity $(E)$ of $3\hat{a_{x}} V/m$?

5 / 162

How is the electric flux density calculated in a vacuum?

6 / 162

Which of the following correctly describes an electric field intensity?

7 / 162

What direction does the gradient of any scalar function point?

8 / 162

What direction does the electric field vector $(\vec{E})$ point?

9 / 162

What is the electric potential at infinity?

10 / 162

Two points A and B are placed on opposite ends of the diameter of a circle. A charge is moved from point A to point B through two paths, one through the perimeter of the circle and another through the diameter. Which path has a higher electric potential difference?

11 / 162

A $2C$ charge is placed at origin and a $1C$charge is being shifted from location $(1,0)$ to $(0,1)$. What is the change in the electric potential of the $1C$ charge?

12 / 162

What is the unit of electric potential?

13 / 162

An electron is revolving in a circular orbit of radius $12$ picometer with an angular velocity of $10^{6}$ radian per second. What is the net work done on the electron by a proton placed at the center of the orbit?

14 / 162

What is the net work done if a $-4 C$ charge is moved from point $(2,2)$ to $(0,0)$ in a region where the electric field is $+10\hat{a}_{x}$?

15 / 162

Which one of the following equations calculates the work done when moving an object from point $A$ to point $B$ under the influence of force $F$?

16 / 162

A hollow sphere has a radius of $1$ $unit$ with a $+2C$ charge at its center and $-2C$ charge at a point $0.5$ $units$ away from its center. What is the total flux through its surface?

17 / 162

Which of the following describes the divergence of the electric flux density?

18 / 162

A Gaussian surface contains one proton and one electron. What is the total flux through this surface? ($Q_{p}$ -charge of a proton, $\epsilon _{o}$ - permittivity of free space)

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Which of the following statements is correct with regards to Gauss's Law?

20 / 162

Which of the following are true for the relationship between electric field and electric flux density?

21 / 162

Which of the following quantities can be calculated by using Gauss's law for electrostatics?

22 / 162

Which of the following charge distribution can be used for a parallel plate capacitor with negligible plate thickness?

23 / 162

What is the unit of volume charge density?

24 / 162

Two point charges $Q_{1}$ and $Q_{2}$ are placed at $(7,3,2)$ and $(4,1,8)$ respectively. What is the unit vector $\hat{a_{12}}$?

25 / 162

Three point charges with a magnitude of $1C$, $-2C$ and $3C$ are placed at $(3,7,6)$, $(2,9,1)$ and $(4,5,8)$ respectively. Find the total force experienced by the $1C$ charge.

26 / 162

If multiple charges are present in a certain region, what is the total electric field equal to?

27 / 162

If multiple charges are present in a certain region, which of the following principles is used to calculate the force experienced by a particular charge?

28 / 162

Two particles with equal and opposite charges of magnitude $1\times 10^{-12} C$ are located $20 cm$ apart. The negative charge is held to the left and the positive charge to the right. What is the magnitude and direction of electric field at the point midway between the charges?

29 / 162

What is the magnitude of a point charge for creating an electric field of $2 N/C$ at a point which is a distance of $1m$ from it?

30 / 162

The force experienced by two charges, $Q1$ and $Q2$, separated by some distance is $F$. What is the force experienced by them if the distance between them is doubled?

31 / 162

What is the value of permittivity of free space?

32 / 162

Which of the following represents a unit of electric flux density?

33 / 162

Which represents a unit of an electric field?

34 / 162

In which direction does the electric field lines travel about a positive charge?

35 / 162

Which type of force occurs when two unlike charges are brought closer together?

36 / 162

What is the magnetic field $B$ at a distance $r$ from an infinite length of wire carrying current $I$?

37 / 162

What is the expression of the magnetic flux density $B$ at a point P for a finite wire carrying current $I$, as shown in the below figure?

38 / 162

What is the expression for force $F_{m}$ on a differential current element $Idl$ in the presence of magnetic flux density $(B)$?

39 / 162

What is the total force $F_{tot}$ experienced by a charged particle $q$, taking into account the possible presence of both magnetic and electric fields?
Where $B$ is the magnetic flux density and $E$ is the electric field intensity.

40 / 162

At what angle in degrees between the magnetic field and the velocity of a moving charge will it experience a maximum force?

41 / 162

Currents of $1A$ and $2A$ are flowing in opposite direction to each other in two concentric coplanar circular loops with radii $1m$ and $2m$. What is the magnitude of magnetic flux density at the center of loop?

42 / 162

Find the magnitude of the magnetic field intensity if the magnetic vector potential is $2\hat{x}+3\hat{y}-\hat{z}$ ?

43 / 162

Which best describes the nature of the magnetic field magnitude at a fixed distance around a straight, current carrying conductor?

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Which equation defines the magnetic field resulting from any arbitrary current source?

45 / 162

Which of the following equation best describes the relation between the magnetic vector potential $(A)$ and the magnetic flux density $(B)$?

46 / 162

A current of $2A$ is flowing through a $12.56m$ long wire formed as a coil of N turns with a diameter $0.2m$. What is the magnetic flux density at its center?

47 / 162

Given the direction of current, how will you determine the direction of magnetic field around a current carrying conductor?

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If current of $3A$ is passing through a circular loop with radius of $0.10m$, find the magnetic field at the center of the circular loop?

49 / 162

Which of the following fields are associated with moving charge particles?

50 / 162

Which of the following laws represent the relationship between the current flowing through a conductor and its associated magnetic field? (Pick the best two)

51 / 162

Which of the following is the expression for Ampere's law?

52 / 162

Which of the following vector equation represents magnetic flux density?

53 / 162

Which of the following law represents the equation $\oint_{S}\vec{B}\cdot \vec{ds} = 0$ ?