Description : The charge build up in a capacitor is due to a) Conduction current density b) Displacement current density c) Polarisation d) Magnetization
Last Answer : b) Displacement current density
Description : The current in a metal at any frequency is due to a) Conduction current b) Displacement current c) Both conduction and displacement current d) Neither conduction nor displacement current
Last Answer : a) Conduction current
Description : Calculate the electric field when the conductivity is 20 units, electron density is 2.4 units and the velocity is 10m/s. Assume the conduction and convection current densities are same. a) 2.4 b) 4.8 c) 3.6 d) 1.2
Last Answer : d) 1.2
Description : The current flowing through an insulating medium is called a) Conduction b) Convection c) Radiation d) Susceptibility
Last Answer : b) Convection
Description : Insulators perform which of the following functions? a) Conduction b) Convection c) Provide electrical insulation d) Allows current leakage at interfaces
Last Answer : c) Provide electrical insulation
Description : Find the loss tangent of a material with conduction current density of 5 units and displacement current density of 10 units. a) 2 b) 0.5 c) 5 d) 10
Last Answer : b) 0.5
Description : At high frequencies, which parameter is significant? a) Conduction current b) Displacement current c) Attenuation constant d) Phase constant
Last Answer : b) Displacement current
Description : Both the conduction and displacement current densities coexist in which medium? a) Only conductors in air b) Only dielectrics in air c) Conductors placed in any dielectric medium d) Both the densities can never coexist
Last Answer : c) Conductors placed in any dielectric medium
Description : When the conduction current density and displacement current density are same, the dissipation factor will be a) Zero b) Minimum c) Maximum d) Unity
Last Answer : d) Unity
Description : The ratio of conduction to displacement current density is referred to as a) Attenuation constant b) Propagation constant c) Loss tangent d) Dielectric constant
Last Answer : c) Loss tangent
Description : Calculate the frequency at which the conduction and displacement currents become equal with unity conductivity in a material of permittivity 2. a) 18 GHz b) 9 GHz c) 36 GHz d) 24 GHz
Last Answer : b) 9 GHz
Description : Find the electron density when convection current density is 120 units and the velocity is 5m/s. a) 12 b) 600 c) 24 d) 720
Last Answer : c) 24
Description : Calculate the convection current when electron density of 200 units is travelling at a speed of 12m/s. a) 16.67 b) 2400 c) 2880 d) 0.0
Last Answer : b) 2400
Description : Conduction in metals is due to a) Electrons only b) Electrons and holes c) Holes only d) Applied electric field
Last Answer : a) Electrons only
Description : Gauss law cannot be used to find which of the following quantity? a) Electric field intensity b) Electric flux density c) Charge d) Permittivity
Last Answer : d) Permittivity
Description : Coulomb is the unit of which quantity? a) Field strength b) Charge c) Permittivity d) Force
Last Answer : b) Charge
Description : At dc field, the displacement current density will be a) 0 b) 1 c) Jc d) ∞
Last Answer : a) 0
Description : Find the equation of displacement current density in frequency domain. a) Jd = jwεE b) Jd = jwεH c) Jd = wεE/j d) Jd = jεE/w
Last Answer : a) Jd = jwεE
Description : Find the displacement current density of a material with flux density of 5sin t a) 2.5cos t b) 2.5sin t c) 5cos t d) 5sin t
Last Answer : c) 5cos t
Description : Find the displacement current when the flux density is given by t 3 at 2 seconds. a) 3 b) 6 c) 12 d) 27
Last Answer : c) 12
Description : Find the magnitude of the displacement current density in air at a frequency of 18GHz in frequency domain. Take electric field E as 4 units. a) 18 b) 72 c) 36 d) 4
Last Answer : d) 4
Description : Calculate the displacement current density when the electric flux density is 20sin 0.5t. a) 10sin 0.5t b) 10cos 0.5t c) 20sin 2t d) 20cos 2t
Last Answer : b) 10cos 0.5t
Description : In reverberatory furnace, charge is heated mainly by (A) Conduction (B) Natural convection (C) Radiation of heat from the roof of the combustion chamber (D) None of these
Last Answer : (C) Radiation of heat from the roof of the combustion chamber
Description : In salt bath furnace, heat is transferred to the charge mainly by (A) Conduction (B) Convection (C) Radiation (D) None of these
Last Answer : (A) Conduction
Description : Calculate the conduction current density when the resistivity of a material with an electric field of 5 units is 4.5 units. a) 22.5 b) 4.5/5 c) 5/4.5 d) 9.5
Last Answer : c) 5/4.5
Description : The magnitude of the conduction current density for a magnetic field intensity of a vector yi + zj + xk will be a) 1.414 b) 1.732 c) -1.414 d) -1.732
Last Answer : b) 1.732
Description : Find the conduction current density of a material with conductivity 200units and electric field 1.5 units. a) 150 b) 30 c) 400/3 d) 300
Last Answer : d) 300
Description : Find the conductivity of a material with conduction current density 100 units and electric field of 4 units. a) 25 b) 400 c) 0.04 d) 1600
Last Answer : a) 25
Description : Find the conduction current density when conductivity of a material is 500 units and corresponding electric field is 2 units. a) 500 b) 250 c) 1000 d) 2000
Last Answer : c) 1000
Description : The loss tangent refers to the a) Power due to propagation in conductor to that in dielectric b) Power loss c) Current loss d) Charge loss
Last Answer : a) Power due to propagation in conductor to that in dielectric
Description : Find the magnetic field intensity due to an infinite sheet of current 5A and charge density of 12j units in the positive y direction and the z component is below the sheet. a) 6 b) 0 c) -6 d) 60k
Last Answer : c) -6
Description : Find the magnetic field intensity due to an infinite sheet of current 5A and charge density of 12j units in the positive y direction and the z component is above the sheet. a) -6 b) 12k c) 60 d) 6
Last Answer : d) 6
Description : Trade winds are due to – (1) Conduction (2) Convection (3) Radiation (4) Scattering
Last Answer : (2) Convection Explanation: The air moving across the surface towards the extra heated region is known as the trade winds. The region where the northern convective airflow meets the southern and the air starts ... drops heavy rain, but since it's moving up instead of across it won't fill sails.
Description : Land and sea-breezes occur due to : (1) Conduction (2) Convection (3) Radiation (4) Tides
Last Answer : (2) Convection Explanation: During the day, the sun warming the land also warms the air. Since land heats up quicker than water does, the air over land gets warmer than the air over the water. ... Breeze. Reversely, at night the land cools down faster than the water does, and creates a Land Breeze.
Description : Even after sunset, the air near the Earth's surface continue to receive heat due to – (1) Insolation (2) Terrestrial Radiation (3) Conduction (4) Convection
Last Answer : (2) Terrestrial Radiation Explanation: Even after the sunset when the sun goes down, the incoming radiation from the sun stops, but there is still a lot of radiation that has been absorbed ... i.e. terrestrial radiation heats up the atmosphere more than the incoming solar radiation i.e. insolation
Description : The mcrease in heat dissipation by air blasts is due to increase in (a) conduction (b) convection (e) radiation (d) any ofthe above
Last Answer : (b) convection
Description : Even after sunset, the air near the Earth’s surface continue to receive heat due to (1) Insolation (2) Terrestrial Radiation (3) Conduction (4) Convection
Last Answer : Terrestrial Radiation
Last Answer : Convection
Description : Trade winds are due to (1) Conduction (2) Convection (3) Radiation (4) Scattering
Description : From the formula F = qE, can prove that work done is a product of force and displacement. State True/False a) True b) False
Last Answer : a) True
Description : Heat transfer in the laminar sub-layer in case of a liquid flowing through a pipe, is mostly by (A) Eddies current (B) Conduction (C) Convection (D) None of these
Last Answer : (B) Conduction
Description : Calculate the conduction density of a material with resistivity of 0.02 units and electric intensity of 12 units. a) 300 b) 600 c) 50 d) 120
Last Answer : b) 600
Description : A boundary of separation between two magnetic materials is identified by which factor? a) Change in the permeability b) Change in permittivity c) Change in magnetization d) Conduction
Last Answer : a) Change in the permeability
Description : For conductors, the free electrons will exist at a) Valence band b) Middle of valence and conduction band c) Will not exist d) Conduction band
Last Answer : d) Conduction band
Description : In case of semi-conductors, the ratio of conduction current to displacement current is: A) more than 200 and less than 1000 B) less than 100 but greater than 1/100 C) less than 1/100 D) more than 1000
Last Answer : In case of semi-conductors, the ratio of conduction current to displacement current is: less than 100 but greater than 1/100
Description : Find the electric field due to charge density of 1/18 and distance from a point P is 0.5 in air(in 10 9 order) a) 0 b) 1 c) 2 d) 3
Last Answer : c) 2
Description : Calculate the electric field due to a surface charge of 20 units on a plate in air(in 10 12 order) a) 2.19 b) 1.12 c) 9.21 d) 2.91
Last Answer : b) 1.12
Description : Find the angle at which the potential due a dipole is measured, when the distance from one charge is 12cm and that due to other is 11cm, separated to each other by a distance of 2cm. a) 15 b) 30 c) 45 d) 60
Last Answer : d) 60
Description : A point charge 0.4nC is located at (2, 3, 3). Find the potential differences between (2, 3, 3)m and (-2, 3, 3)m due to the charge. a) 2.5 b) 2.6 c) 2.7 d) 2.8
Last Answer : c) 2.7
Description : Electric field intensity due to infinite sheet of charge σ is a) Zero b) Unity c) σ/ε d) σ/2ε
Last Answer : d) σ/2ε