If charge is distributed over a (curved) line, each differential charge dQ along the line produces a differential electric field:

\(dE = \frac{{dQ\;{r^2}}}{{4\pi \varepsilon }}{\hat a_r}\)

\(dE = \frac{{dQ}}{{4\pi \varepsilon {r^2}}}{\hat a_r}\)

\(dE = \frac{{dQ\;{r^2}}}{{4\pi \varepsilon }}{\hat a_r}\)

\(dE = \frac{{dQ}}{{{r^2}}}{\hat a_r}\)

\(dE = \frac{{dQ}}{{4\pi \varepsilon r}}{\hat a_r}\)

A point charge is located at the origin. At point (a, a), the electric field is E1. At point (-a, a) the electric field is E2 and at a point (-a, -a) the electric field is E3.Which one of the following is correct?

Neither E1 ⋅ E2 = 0 nor |E1 × E3| = 0

Both E1 ⋅ E2 = 0 and |E1 × E3| = 0

Neither E1 ⋅ E2 = 0 nor |E1 × E3| = 0

Consider two concentric spherical conductors with the inner sphere of diameter 1 m and the outer sphere of diameter 2 m. Assume +Q and -Q Coulomb charges on the inner and outer spheres and also that they are separated by a dielectric medium with permittivity ε F/m. The capacitance of this spherical capacitor in Farad is

\(\dfrac{2\pi\varepsilon}{\ln 2}\)

For electromechanical energy conversion, a magnetic field is employed as the medium rather than electric field because

The electric field presents insulator problem

The stored energy density for practicable field strength is low in the electric field

The electric field presents insulator problem

The specific magnetic loss is more than the specific dielectric loss

An infinite number of concentric rings carry a charge Q each alternately positive and negative. Their radii are 1, 2, 4, 8 … metres in geometric progression as shown below:The potential at the centre is

\(\frac{Q}{{12\pi {\varepsilon _0}}}\)

\(\frac{Q}{{8\pi {\varepsilon _0}}}\)

\(\frac{Q}{{6\pi {\varepsilon _0}}}\)

In the region Z 0, where ϵr2 = 6.5, \(\vec E_2\) is

\({\vec E_2} = - 3{\vec a_x} + 4{\vec a_y} + \frac{4}{{6.5}}{\vec a_z}\)

\({\vec E_2} = - 3{\vec a_x} + 4{\vec a_y} + \frac{6.5}{{4}}{\vec a_z}\)

\({\vec E_2} = - 3{\vec a_x} + 4{\vec a_y} - \frac{6.5}{{4}}{\vec a_z}\)

\({\vec E_2} = - 3{\vec a_x} + 4{\vec a_y} - \frac{4}{{6.5}}{\vec a_z}\)

An electrostatic force between two point charges increases when they are:

More apart and dielectric constant of the medium between them increases

More apart and dielectric constant of the medium between them decreases

Less apart and dielectric constant of the medium between them decreases

More apart and dielectric constant of the medium between them increases

Less apart and dielectric constant of the medium between them increases

For current flowing through semi-conductor, which of the following statement is true

Conduction Current + Diffusion Current

A charge q1, exerts some force on a second charge q2. Now, if a third charge q3 is brought near, then the force exerted by q1 on q2:

will increase if q3 is of the same sign as q1 and will decrease if q3 is of opposite charge to q1

For a homogeneous and isotropic medium with a charge density ρ & dielectric constant ε, the Poisson's equation for electrical potential V is:

\(\nabla.V = \frac {\rho}{\varepsilon}\)

\(\nabla^2V = \frac {\rho}{\varepsilon}\)

\(\nabla^2V = -\frac {\rho}{\varepsilon}\)

\(\nabla.V = \frac {\rho}{\varepsilon}\)

\(\nabla.V = -\frac {\rho}{\varepsilon}\)

If there are more than one charge distribution in Gaussian surface, the net charge is:

Algebraic sum of all the odd charges

Algebraic sum of all the even charges

Algebraic sum of all the individual charges

Algebraic sum of all the odd charges

A potential field is given by V = 3x2y – yz. Find the electric field at (1, 0, -1)

\( - 3{\hat a_x} - 3{\hat a_y}\)

Match List I with List II and select the correct answer using the code given below the lists: List I List IIA.Characteristic impedance1.Δ.D = ρvB.Poynting vector2.\({\sqrt\frac{j\omega \mu}{\sigma+j\omega\epsilon}}\)C.Displacement current3.E × HD.Point form of Gauss law4.\(\frac{dD}{dt}\)

A – 1, B – 3, C – 4, D - 2

A – 2, B – 3, C – 4, D - 1

A – 1, B – 3, C – 4, D - 2

A – 2, B – 4, C – 3, D - 1

A – 1, B – 4, C – 3, D - 2

255 + Mcqs in Electrostatics in UPSEE Page 1 McqOptions

1.	A hollow metallic sphere of radius r is kept at potential of 1 Volt. The total electric flux coming out of the concentric spherical surface of radius R (> r) is
A.	4πε0r
B.	4πε0r2
C.	4πε0R
D.	4πε0R2
Answer» B. 4πε0r2

Discussion

2.	A parallel plate capacitor has plates of dimensions 2 cm by 3 cm, separated by a 1 mm thickness of a paper with relative permittivity 3.7. The permittivity of free space, ε0 = 8.85 × 10-12 C2/Nm2. Find the capacitance.
A.	20 pF
B.	20 μF
C.	10 nF
D.	10 μF
Answer» B. 20 μF

Discussion

3.	Consider the following:1) Electric current flowing in a conducting wire.2) A moving charged belt3) An electron beam in a cathode-ray tube4) Electron movement in a vacuum tubeWhich of the above are examples of convection current?
A.	2, 3 and 4 only
B.	1, 2 and 4 only
C.	1 and 3only
D.	1, 2, 3 and 4
Answer» B. 1, 2 and 4 only

Discussion

4.	An electric field is mentioned as E = (6y2 zax + 12xyz ay + 6xy2 az) V/m an incremental path is represented by ΔL = (-3ax + 5ay – 2az) μm. What is the work done in moving 2μC charge along the path if the location of the path is P(0, 2, 5).
A.	360 pJ
B.	540 μJ
C.	720 pJ
D.	360 μJ
Answer» D. 360 μJ

Discussion

5.	Consider the following statements:The force per unit length between two stationary parallel wires carrying (steady) currents _____.A. is inversely proportional to the separation of wiresB. is proportional to the magnitude of each currentC. satisfies Newton's third lawOut of this _____.
A.	A and B are correct
B.	B and C are correct
C.	A and C are correct
D.	A, B and C are correct
Answer» E.

Discussion

6.	A charge 'Q' is divided between two point charges. What should be the values of this charge on the objects so that the force between them is maximum?
A.	Q / 3
B.	Q / 2
C.	(Q - 2)
D.	2Q
Answer» C. (Q - 2)

Discussion

7.	If charge is distributed over a (curved) line, each differential charge dQ along the line produces a differential electric field:
A.	\(dE = \frac{{dQ}}{{4\pi \varepsilon {r^2}}}{\hat a_r}\)
B.	\(dE = \frac{{dQ\;{r^2}}}{{4\pi \varepsilon }}{\hat a_r}\)
C.	\(dE = \frac{{dQ}}{{{r^2}}}{\hat a_r}\)
D.	\(dE = \frac{{dQ}}{{4\pi \varepsilon r}}{\hat a_r}\)
Answer» B. \(dE = \frac{{dQ\;{r^2}}}{{4\pi \varepsilon }}{\hat a_r}\)

Discussion

8.	A point charge is located at the origin. At point (a, a), the electric field is E1. At point (-a, a) the electric field is E2 and at a point (-a, -a) the electric field is E3.Which one of the following is correct?
A.	E1 ⋅ E2 = 0
B.	\|E1 × E3\| = 0
C.	Both E1 ⋅ E2 = 0 and \|E1 × E3\| = 0
D.	Neither E1 ⋅ E2 = 0 nor \|E1 × E3\| = 0
Answer» D. Neither E1 ⋅ E2 = 0 nor \|E1 × E3\| = 0

Discussion

9.	A Charge of 2 Coulombs is placed near a ground conducting plate at a distance of 1 m. The force acting between the charge of 2 C and ground conducting plate in Newton is
A.	\(\frac{1}{4\pi \epsilon}\)
B.	\(\frac{1}{8\pi \epsilon}\)
C.	\(\frac{1}{16\pi \epsilon}\)
D.	4πϵ
Answer» B. \(\frac{1}{8\pi \epsilon}\)

Discussion

10.	Consider two concentric spherical conductors with the inner sphere of diameter 1 m and the outer sphere of diameter 2 m. Assume +Q and -Q Coulomb charges on the inner and outer spheres and also that they are separated by a dielectric medium with permittivity ε F/m. The capacitance of this spherical capacitor in Farad is
A.	4πε
B.	8πε
C.	\(\dfrac{2\pi\varepsilon}{\ln 2}\)
D.	Q/2
Answer» B. 8πε

Discussion

11.	In cylindrical coordinate system, the potential produced by a uniform ring charge is given by \(\;\phi = \;f\left( {r,z} \right)\), where \(f\) is a continuous function of \(r\) and \(z\). Let \(\vec E\) be the resulting electric field. Then the magnitude of \(\nabla \times {\rm{\vec E}}\)
A.	increases with r
B.	is 0
C.	is 3
D.	decreases with z
Answer» C. is 3

Discussion

12.	Assuming zero voltage at infinity, find the potential at P(0, 0, 10) that is caused by a charge distribution of 10 nC/m along the line x = 0, y = 0, -1 < z > 1 in free space.
A.	18 V
B.	8 V
C.	5 V
D.	20 V
Answer» B. 8 V

Discussion

13.	Match List I with List II and select the correct answer using the code given below the list.List IList IIA. MMF1. ConductivityB. Magnetic flux2. Electric currentC. Reluctance3. EMFD. Permeability4. Resistance
A.	A - 3, B - 4, C - 2, D - 1
B.	A - 1, B - 2, C - 4, D - 3
C.	A - 3, B - 2, C - 4, D - 1
D.	A - 1, B - 4, C - 2, D - 3
Answer» D. A - 1, B - 4, C - 2, D - 3

Discussion

14.	Calculate the surface charge density at point (2, -1, -3) at the boundary surface of a conductor and free space if the potential field is given by V = 100 (x2 – y2).
A.	7.8 nc/m2
B.	-7.8 nc/m2
C.	3.96 nc/m2
D.	-3.96 nc/m2
Answer» D. -3.96 nc/m2

Discussion

15.	For electromechanical energy conversion, a magnetic field is employed as the medium rather than electric field because
A.	The stored energy density for practicable field strength is low in the electric field
B.	The electric field presents insulator problem
C.	The specific magnetic loss is more than the specific dielectric loss
D.	None of the above
Answer» B. The electric field presents insulator problem

Discussion

16.	An infinite number of concentric rings carry a charge Q each alternately positive and negative. Their radii are 1, 2, 4, 8 … metres in geometric progression as shown below:The potential at the centre is
A.	0
B.	\(\frac{Q}{{12\pi {\varepsilon _0}}}\)
C.	\(\frac{Q}{{8\pi {\varepsilon _0}}}\)
D.	\(\frac{Q}{{6\pi {\varepsilon _0}}}\)
Answer» E.

Discussion

17.	How many coulombs of charge do 25 × 1031 electrons possess?
A.	80 × 1012 C
B.	4 × 1012 C
C.	40 × 1012 C
D.	8 × 1012 C
Answer» D. 8 × 1012 C

Discussion

18.	If the potential, V = - 4x + 2 volts, the electric filed is
A.	6 V/m
B.	2 V/m
C.	4 V/m
D.	4a̅x V/m
Answer» E.

Discussion

19.	If a charge of 2 C is placed at a point and the charge have electrical potential energy of 20 J, then determine the electric potential.
A.	30 V
B.	20 V
C.	5 V
D.	10 V
Answer» E.

Discussion

20.	In the region Z < 0, ϵr1 = 2, \({\vec E_1} = - 3{\vec a_x} + 4{\vec a_y} - 2{\vec a_z} \) V/m. For a region Z > 0, where ϵr2 = 6.5, \(\vec E_2\) is
A.	\({\vec E_2} = - 3{\vec a_x} + 4{\vec a_y} + \frac{4}{{6.5}}{\vec a_z}\)
B.	\({\vec E_2} = - 3{\vec a_x} + 4{\vec a_y} + \frac{6.5}{{4}}{\vec a_z}\)
C.	\({\vec E_2} = - 3{\vec a_x} + 4{\vec a_y} - \frac{6.5}{{4}}{\vec a_z}\)
D.	\({\vec E_2} = - 3{\vec a_x} + 4{\vec a_y} - \frac{4}{{6.5}}{\vec a_z}\)
Answer» E.

Discussion

21.	A circular cross-section conductor of radius 1.5 mm carries a current of 5.5 sin (4 × 1010t)μA. What is the amplitude of the displacement current (JD) density if σ (conductivity) is 35 MS/m and εr = 1?
A.	7.86 × 10-3 μA/m2
B.	-7.86 × 10-3 μA/m2
C.	7.86 μA/m2
D.	78.6 μA/m2
Answer» B. -7.86 × 10-3 μA/m2

Discussion

22.	A sphere of the homogenous linear dielectric material of dielectric constant ≥ 1 1 is placed in a uniform electric field E0, then the electric field E that exists inside the sphere is:
A.	Uniform and E ≤ E0
B.	Uniform and E ≥ E0
C.	Varies but E < E0 always
D.	Varies but E > E0 always
Answer» B. Uniform and E ≥ E0

Discussion

23.	If the relative permittivity of the medium increases, the electric intensity at a point due to a given charge
A.	decreases
B.	increases
C.	remains the same
D.	none
Answer» B. increases

Discussion

24.	A parallel plate capacitor of area A cm2 and separating distance a cm is dipped in ethyl alcohol up to a depth of a / 2. Given the dielectric constant εr of ethyl alcohol to be 25, the ratio of capacitance after dipping to that before dipping would be
A.	26 / 50
B.	45 / 50
C.	50 / 26
D.	3 / 1
Answer» D. 3 / 1

Discussion

25.	An electrostatic force between two point charges increases when they are:
A.	More apart and dielectric constant of the medium between them decreases
B.	Less apart and dielectric constant of the medium between them decreases
C.	More apart and dielectric constant of the medium between them increases
D.	Less apart and dielectric constant of the medium between them increases
Answer» C. More apart and dielectric constant of the medium between them increases

Discussion

26.	For current flowing through semi-conductor, which of the following statement is true
A.	Only conduction current
B.	Only Diffusion Current
C.	Conduction Current + Diffusion Current
D.	None of the above
Answer» D. None of the above

Discussion

27.	A circular disk of radius 4 m with a charge density ρs = 12 sin ϕ μC/m2 is enclosed by surface S. What net flux crosses S?
A.	32 π μ C
B.	12 μ Ck
C.	32 × 12 π μ C
D.	0 C
Answer» E.

Discussion

28.	Given the electric field E = 2xax - 4yay (V/m), find the work done in moving a point charge of 2 C from (2, 0, 0) m to (0, 0, 0) m and then from (0, 0, 0) m to (0, 2, 0) m.
A.	- 8 J
B.	16 J
C.	24 J
D.	8 J
Answer» D. 8 J

Discussion

29.	According to Gauss’s law, if E is _________, the charge density in the ideal conductor is zero.
A.	positive
B.	negative
C.	zero
D.	unity
Answer» D. unity

Discussion

30.	A charge q1, exerts some force on a second charge q2. Now, if a third charge q3 is brought near, then the force exerted by q1 on q2:
A.	will increase in magnitude
B.	will decrease in magnitude
C.	will remain unaffected
D.	will increase if q3 is of the same sign as q1 and will decrease if q3 is of opposite charge to q1
Answer» D. will increase if q3 is of the same sign as q1 and will decrease if q3 is of opposite charge to q1

Discussion

31.	A point charge of +3 μC and -3 μC are located at (0, 0, 1) and (0, 0, -1) respectively, in free space. Find the magnitude of dipole moment. Consider distances in meters
A.	12 μCm
B.	6 μCm
C.	18 μCm
D.	3 μCm
Answer» C. 18 μCm

Discussion

32.	For a homogeneous and isotropic medium with a charge density ρ & dielectric constant ε, the Poisson's equation for electrical potential V is:
A.	\(\nabla^2V = \frac {\rho}{\varepsilon}\)
B.	\(\nabla^2V = -\frac {\rho}{\varepsilon}\)
C.	\(\nabla.V = \frac {\rho}{\varepsilon}\)
D.	\(\nabla.V = -\frac {\rho}{\varepsilon}\)
Answer» C. \(\nabla.V = \frac {\rho}{\varepsilon}\)

Discussion

33.	Consider the following statements with respect to boundary conditions between two materials of different permeabilities in magnetic circuits. State whether these statements are true or false.(i) The normal component of flux density is continuous across the boundary.(ii) The tangential component of magnetic field strength is continuous across the boundary.
A.	(i) True, (ii) False
B.	(i) False, (ii) False
C.	(i) True, (ii) True
D.	(i) False, (ii) True
Answer» D. (i) False, (ii) True

Discussion

34.	A point charge Q is at the origin of a spherical co-ordinate system. Find the net flux that crosses the portion of the spherical shell described by \(0\le \theta \le \frac{\pi }{2}\).
A.	Q
B.	Q/2
C.	Q/4
D.	Q2
Answer» C. Q/4

Discussion

35.	Consider the following image. It is known that two concentric spherical shells carry equal and opposite uniformly distributed charges over their surfaces. What will be the electric field on the surface of the inner shell?
A.	Zero
B.	Q/(4πR2)
C.	Q/(2πR2)
D.	2Q/(πR2)
Answer» B. Q/(4πR2)

Discussion

36.	A material has conductivity of 10-2 mho/m and a relative permittivity of 4. The frequency at which the conduction current in the medium is equal to the displacement current is
A.	45 MHz
B.	90 MHz
C.	450 MHz
D.	900 MHz
Answer» B. 90 MHz

Discussion

37.	If there are more than one charge distribution in Gaussian surface, the net charge is:
A.	Algebraic sum of all the even charges
B.	Difference of all the charges
C.	Algebraic sum of all the individual charges
D.	Algebraic sum of all the odd charges
Answer» D. Algebraic sum of all the odd charges

Discussion

38.	Magnetic flux through any closed surface is ________.
A.	One
B.	Infinite
C.	Zero
D.	Negative
Answer» D. Negative

Discussion

39.	Find the relative permittivity of dielectric material used in a parallel plate capacitor if electric flux density D = 15 μC/m2 and energy density is 20 J/m3.
A.	0.6
B.	0.8
C.	0.9
D.	1.1
Answer» B. 0.8

Discussion

40.	A charge Q is enclosed by a Gaussian spherical surface of radius R. If R is doubled then the outward flux is
A.	Doubled
B.	Increased four times
C.	Reduced to a quarter
D.	Remains unaltered
Answer» E.

Discussion

41.	If the potential difference between points A (1, 0, 0) and B(2, 0 0) is 10 V, determine d for point C(D, 0, 0), when VBC is 6 V in a uniform field
A.	1 m
B.	2 m
C.	6 m
D.	5 m
Answer» E.

Discussion

42.	Electric Field is defined as
A.	Potential per unit charge
B.	Force Per Unit Charge
C.	Voltage per unit Current
D.	None of These
Answer» C. Voltage per unit Current

Discussion

43.	A positive charge of 1 nC is placed at (0, 0, 0.2) where all dimensions are in metres. Consider the x – y plane to be a conducting ground plane. Take \({ \in _0} = 8.85 \times {10^{ - 12}}\) F/M. The z component of the E field at (0, 0, 0.1) is closest to
A.	899.18 V/m
B.	-899.18 V/m
C.	999.09 V/m
D.	-999.09 V/m
Answer» E.

Discussion

44.	A dielectric material is placed in vacuum in a uniform electric field of E = 4 V/m. What is the electric field inside the material if the relative permittivity of dielectric material is 2?
A.	Zero
B.	4 V/m
C.	2 V/m
D.	8 V/m
Answer» D. 8 V/m

Discussion

45.	A potential field is given by V = 3x2y – yz. Find the electric field at (1, 0, -1)
A.	\(4{\hat a_z}\)
B.	\( - 3{\hat a_x} - 3{\hat a_y}\)
C.	\( - 4{\hat a_y}\)
D.	\(3{\hat a_x} + 3{\hat a_y}\)
Answer» D. \(3{\hat a_x} + 3{\hat a_y}\)

Discussion

46.	Match List I with List II and select the correct answer using the code given below the lists: List I List IIA.Characteristic impedance1.Δ.D = ρvB.Poynting vector2.\({\sqrt\frac{j\omega \mu}{\sigma+j\omega\epsilon}}\)C.Displacement current3.E × HD.Point form of Gauss law4.\(\frac{dD}{dt}\)
A.	A – 2, B – 3, C – 4, D - 1
B.	A – 1, B – 3, C – 4, D - 2
C.	A – 2, B – 4, C – 3, D - 1
D.	A – 1, B – 4, C – 3, D - 2
Answer» B. A – 1, B – 3, C – 4, D - 2

Discussion

47.	Find the radius of an isolated sphere capable of being charged to 1 million volt potential before sparking into the air, given that breakdown voltage of air is 3 × 104 V/cm
A.	0.33 metre
B.	0.43 metre
C.	0.53 metre
D.	0.63 metre
Answer» B. 0.43 metre

Discussion

48.	An electric field is given by E = zy2ax + 2xyz ay+ xy2az V/m, an incremental path is represented by ΔL = -3ax + 5ay – 2az μm. Find the work done in moving 4 μC charge along the incremental path if the location of the path is at point P(1, 1, 1).
A.	20 pJ
B.	40 pJ
C.	-40 pJ
D.	-20 pJ
Answer» E.

Discussion

49.	A force with which the plates of a parallel plate capacitor having charge Q and area of each plate A, attract each other is:(a) Directly proportional to Q(b) Inversely proportional to Q(c) Directly proportional to Q2(d) Inversely proportional to AWhich of the above are correct?
A.	(a) and (d) Only
B.	(b) and (d) Only
C.	(c) and (d) Only
D.	(a), (c) and (d) Only
Answer» D. (a), (c) and (d) Only

Discussion

50.	Charge in the form of a plane sheet with density ρs = 40 μC/m2 is located at z = -0.5 m. A uniform line charge of ρl = -6 μC/m lies along the y axis. What net flux crosses the surface of a cube 2 m on an edge, centered at the origin?
A.	172 μC
B.	148 μC
C.	160 μC
D.	10 μC
Answer» C. 160 μC

Discussion

Explore topic-wise MCQs in UPSEE.

A hollow metallic sphere of radius r is kept at potential of 1 Volt. The total electric flux coming out of the concentric spherical surface of radius R (> r) is

A parallel plate capacitor has plates of dimensions 2 cm by 3 cm, separated by a 1 mm thickness of a paper with relative permittivity 3.7. The permittivity of free space, ε0 = 8.85 × 10-12 C2/Nm2. Find the capacitance.

Consider the following:1) Electric current flowing in a conducting wire.2) A moving charged belt3) An electron beam in a cathode-ray tube4) Electron movement in a vacuum tubeWhich of the above are examples of convection current?

An electric field is mentioned as E = (6y2 zax + 12xyz ay + 6xy2 az) V/m an incremental path is represented by ΔL = (-3ax + 5ay – 2az) μm. What is the work done in moving 2μC charge along the path if the location of the path is P(0, 2, 5).

Consider the following statements:The force per unit length between two stationary parallel wires carrying (steady) currents _____.A. is inversely proportional to the separation of wiresB. is proportional to the magnitude of each currentC. satisfies Newton's third lawOut of this _____.

A charge 'Q' is divided between two point charges. What should be the values of this charge on the objects so that the force between them is maximum?

If charge is distributed over a (curved) line, each differential charge dQ along the line produces a differential electric field:

A point charge is located at the origin. At point (a, a), the electric field is E1. At point (-a, a) the electric field is E2 and at a point (-a, -a) the electric field is E3.Which one of the following is correct?

A Charge of 2 Coulombs is placed near a ground conducting plate at a distance of 1 m. The force acting between the charge of 2 C and ground conducting plate in Newton is

In cylindrical coordinate system, the potential produced by a uniform ring charge is given by \(\;\phi = \;f\left( {r,z} \right)\), where \(f\) is a continuous function of \(r\) and \(z\). Let \(\vec E\) be the resulting electric field. Then the magnitude of \(\nabla \times {\rm{\vec E}}\)

Assuming zero voltage at infinity, find the potential at P(0, 0, 10) that is caused by a charge distribution of 10 nC/m along the line x = 0, y = 0, -1 < z > 1 in free space.

Match List I with List II and select the correct answer using the code given below the list.List IList IIA. MMF1. ConductivityB. Magnetic flux2. Electric currentC. Reluctance3. EMFD. Permeability4. Resistance

Calculate the surface charge density at point (2, -1, -3) at the boundary surface of a conductor and free space if the potential field is given by V = 100 (x2 – y2).

For electromechanical energy conversion, a magnetic field is employed as the medium rather than electric field because

An infinite number of concentric rings carry a charge Q each alternately positive and negative. Their radii are 1, 2, 4, 8 … metres in geometric progression as shown below:The potential at the centre is

How many coulombs of charge do 25 × 1031 electrons possess?

If the potential, V = - 4x + 2 volts, the electric filed is

If a charge of 2 C is placed at a point and the charge have electrical potential energy of 20 J, then determine the electric potential.

In the region Z < 0, ϵr1 = 2, \({\vec E_1} = - 3{\vec a_x} + 4{\vec a_y} - 2{\vec a_z} \) V/m. For a region Z > 0, where ϵr2 = 6.5, \(\vec E_2\) is

A circular cross-section conductor of radius 1.5 mm carries a current of 5.5 sin (4 × 1010t)μA. What is the amplitude of the displacement current (JD) density if σ (conductivity) is 35 MS/m and εr = 1?

A sphere of the homogenous linear dielectric material of dielectric constant ≥ 1 1 is placed in a uniform electric field E0, then the electric field E that exists inside the sphere is:

If the relative permittivity of the medium increases, the electric intensity at a point due to a given charge

A parallel plate capacitor of area A cm2 and separating distance a cm is dipped in ethyl alcohol up to a depth of a / 2. Given the dielectric constant εr of ethyl alcohol to be 25, the ratio of capacitance after dipping to that before dipping would be

An electrostatic force between two point charges increases when they are:

For current flowing through semi-conductor, which of the following statement is true

A circular disk of radius 4 m with a charge density ρs = 12 sin ϕ μC/m2 is enclosed by surface S. What net flux crosses S?

Given the electric field E = 2xax - 4yay (V/m), find the work done in moving a point charge of 2 C from (2, 0, 0) m to (0, 0, 0) m and then from (0, 0, 0) m to (0, 2, 0) m.

According to Gauss’s law, if E is _________, the charge density in the ideal conductor is zero.

A charge q1, exerts some force on a second charge q2. Now, if a third charge q3 is brought near, then the force exerted by q1 on q2:

A point charge of +3 μC and -3 μC are located at (0, 0, 1) and (0, 0, -1) respectively, in free space. Find the magnitude of dipole moment. Consider distances in meters

For a homogeneous and isotropic medium with a charge density ρ & dielectric constant ε, the Poisson's equation for electrical potential V is:

A point charge Q is at the origin of a spherical co-ordinate system. Find the net flux that crosses the portion of the spherical shell described by \(0\le \theta \le \frac{\pi }{2}\).

Consider the following image. It is known that two concentric spherical shells carry equal and opposite uniformly distributed charges over their surfaces. What will be the electric field on the surface of the inner shell?

A material has conductivity of 10-2 mho/m and a relative permittivity of 4. The frequency at which the conduction current in the medium is equal to the displacement current is

If there are more than one charge distribution in Gaussian surface, the net charge is:

Magnetic flux through any closed surface is ________.

Find the relative permittivity of dielectric material used in a parallel plate capacitor if electric flux density D = 15 μC/m2 and energy density is 20 J/m3.

A charge Q is enclosed by a Gaussian spherical surface of radius R. If R is doubled then the outward flux is

If the potential difference between points A (1, 0, 0) and B(2, 0 0) is 10 V, determine d for point C(D, 0, 0), when VBC is 6 V in a uniform field

Electric Field is defined as

A positive charge of 1 nC is placed at (0, 0, 0.2) where all dimensions are in metres. Consider the x – y plane to be a conducting ground plane. Take \({ \in _0} = 8.85 \times {10^{ - 12}}\) F/M. The z component of the E field at (0, 0, 0.1) is closest to

A dielectric material is placed in vacuum in a uniform electric field of E = 4 V/m. What is the electric field inside the material if the relative permittivity of dielectric material is 2?

A potential field is given by V = 3x2y – yz. Find the electric field at (1, 0, -1)

Match List I with List II and select the correct answer using the code given below the lists: List I List IIA.Characteristic impedance1.Δ.D = ρvB.Poynting vector2.\({\sqrt\frac{j\omega \mu}{\sigma+j\omega\epsilon}}\)C.Displacement current3.E × HD.Point form of Gauss law4.\(\frac{dD}{dt}\)

Find the radius of an isolated sphere capable of being charged to 1 million volt potential before sparking into the air, given that breakdown voltage of air is 3 × 104 V/cm

An electric field is given by E = zy2ax + 2xyz ay+ xy2az V/m, an incremental path is represented by ΔL = -3ax + 5ay – 2az μm. Find the work done in moving 4 μC charge along the incremental path if the location of the path is at point P(1, 1, 1).

A force with which the plates of a parallel plate capacitor having charge Q and area of each plate A, attract each other is:(a) Directly proportional to Q(b) Inversely proportional to Q(c) Directly proportional to Q2(d) Inversely proportional to AWhich of the above are correct?

Charge in the form of a plane sheet with density ρs = 40 μC/m2 is located at z = -0.5 m. A uniform line charge of ρl = -6 μC/m lies along the y axis. What net flux crosses the surface of a cube 2 m on an edge, centered at the origin?

Consider the following statements:The force per unit length between two stationary parallel wires carrying (steady) currents _.A. is inversely proportional to the separation of wiresB. is proportional to the magnitude of each currentC. satisfies Newton's third lawOut of this _.