Dimensions of ε0 εdϕεdt are of - Physics

Advertisements
Advertisements
MCQ

Dimensions of ε0 `(d phi_ε)/(dt)` are of

Options

  • Potential

  • Charge

  • Capacitance

  • Current

Advertisements

Solution

Current

Explanation:

`(ε_0d phi_ε)/(dt) = (ε_0 EA)/(dt  4piε_0 r^2)`

= `(M^-1L^-3T^4A^2)/(M^-1L^-3A^2) xx (A^1T^1)/L^2 xx L^2/T`

= A = Current

  Is there an error in this question or solution?

RELATED QUESTIONS

Arrange the following electromagnetic wave in the order of their increasing wavelength:

(a) γ- rays

(b) Microwaves

(c) X-rays

(d) Radio waves


A charged particle oscillates about its mean equilibrium position with a frequency of 109 Hz. What is the frequency of the electromagnetic waves produced by the oscillator?


How is the speed of em-waves in vacuum determined by the electric and magnetic field?


In the study of a photoelectric effect the graph between the stopping potential V and frequency v of the incident radiation on two different metals P and Q is shown below:

(i) Which one of the two metals has higher threshold frequency?

(ii) Determine the work function of the metal which has greater value.

(iii) Find the maximum kinetic energy of electron emitted by light of frequency 8 × 1014 Hz for this metal.


Do electromagnetic waves carry energy and momentum ?


Identify the electromagnetic waves whose wavelengths vary as:

(a) 10–12 m < λ < 10–8 m

(b) 10–3 m < λ < 10–1 m

Write one use for each.


What is the ratio of the speed of gamma rays to that of radio waves in a vacuum?


How are electric vector `(vec "E")`, magnetic vector `(vec "B")` and velocity vector `(vec "C")` oriented in an electromagnetic wave?


Write the following radiations in ascending order with respect to their frequencies:

X-rays, microwaves, UV rays and radio waves.


A wire carries an alternating current i = i0 sin ωt. Is there an electric field in the vicinity of the wire?


An electromagnetic wave going through vacuum is described by
E = E0 sin (kx − ωt); B = B0 sin (kx − ωt).
Which of the following equations is true?


Which of the following have zero average value in a plane electromagnetic wave?
(a) Electric field
(b) Magnetic field
(c) Electric energy
(d) Magnetic energy


The energy contained in a small volume through which an electromagnetic wave is passing oscillates with


A point charge is moving along a straight line with a constant velocity v. Consider a small area A perpendicular to the motion of the charge. Calculate the displacement current through the area when its distance from the charge is x. The value of x is not large, so that the electric field at any instant is essentially given by Coulomb's law.


Consider the situation of the previous problem. Define displacement resistance Rd = V/idof the space between the plates, where V is the potential difference between the plates and id is the displacement current. Show that Rd varies with time as `R_d = R(e^(t"/"tau) - 1)` .


A laser beam has intensity 2.5 × 1014 W m−2. Find amplitudes of electric and magnetic fields in the beam.


The energy associated with light of which of the following colours is minimum : 


This is an example of step-up transformer .


Define frequency modulation and state any one advantage of frequency modulation (FM) over amplitude modulation (AM). 


State any one property which is common to all electromagnetic waves.


The energy levels of an atom of a certain element are shown in the given figure. Which one of the transitions A, B, C, D or E will result in the emission of photons of electromagnetic radiation of wavelength 618.75 nm? Support your answer with mathematical calculations.


The dimension of `1/(mu_0 ∈_0)` is


Which of the following electromagnetic radiations is used for viewing objects through fog ______.


Consider an oscillator which has a charged particle oscillating about its mean position with a frequency of 300 MHz. The wavelength of electromagnetic waves produced by this oscillator is ______.


In an electromagnetic wave in free space the rms value of the electric field is 3 V m-1. The peak value of the magnetic field is ______.


An e.m. wave is propagating in a medium with a velocity `vec"v" = "v" hat"i"`. The instantaneous oscillating electric field of this e.m. wave is along +y-axis, then the direction of an oscillating magnetic field of the e.m. wave will be along:


Fraunhofer lines are an example of _______ spectrum.


The electric and magnetic fields of an electromagnetic wave are ______.


What are Fraunhofer lines? How are they useful in the identification of elements present in the Sun?


Write a short note on the radio waves.


Write a short note on the visible spectrum.


The electric field of a plane electromagnetic wave travelling in +ve z-direction is described by ______.


The magnetic field of a plane electromagnetic wave travelling in +ve z-direction is described by ______.


In plane electromagnetic wave propagation velocity v, wavelength λ and frequency ν are related by ______.


A man standing on the road has to hold his umbrella at 30° with the vertical to keep the rain away. He throws away the umbrella and starts, running at 10 km/h and finds raindrops hitting his head vertically. The speed of the raindrops with respect to the road is ______.


Which one of the following does not represent simple harmonic motion? Here y denotes the instantaneous displacement. Here, A and B are constants and co is the angular frequency.


In space communication, the sound waves can be sent from one place to another


A plane electromagnetic wave travels in free space along x-axis. At a particular point in space, the electric field along y-axis is 9.3 Vm−1. The magnetic induction (B) along z-axis is:


An accelerate electron would produce.


The velocity of light in vacuum can be changed by changing


The velocity of electromagnetic wave is parallel to


Which of the following are not electromagnetic waves?


The sun delivers 103w/m2 of electromagnetic flux to the earth's surface. The total power that is incident on a roof of dimension 8m/10m will be


For which frequency of light, the eye is most sensitive?


Electromagnetic waves are produced by ______.


Which of the following type of radiations are radiated by an oscillating electric charge?


For a plane electromagnetic wave propagating in x-direction, which one of the following combinations gives the correct possible directions for electric field (E) and magnetic field (B) respectively?


For a plane electromagnetic wave propagating in the x-direction, which one of the following combinations gives the correct possible directions for the electric field (E) and magnetic field (B) respectively?


Light with an energy flux of 20 W/cm2 falls on a non-reflecting surface at normal incidence. If the surface has an area of 30 cm2 the total momentum delivered (for complete absorption) during 30 minutes is ______.


An EM wave radiates outwards from a dipole antenna, with E0 as the amplitude of its electric field vector. The electric field E0 which transports significant energy from the source falls off as ______.


For an electromagnetic wave travelling in free space, the relation between average energy densities due to electric (Ue) and magnetic (Um) fields is ______.


A plane electromagnetic wave, has frequency of 2.0 × 1010 Hz and its energy density is 1.02 × 10-8 J/m3 in vacuum. The amplitude of the magnetic field of the wave is close to `(1/(4piepsilon_0) = 9xx10^9"Nm"^2/"C"^2  "and speed of light" = 3 xx 10^8  "m"  "s"^-1)`:


The electric field in a plane electromagnetic wave is given by `vecE = 200cos[((0.5 xx 10^3)/m)x - (1.5 xx 10^11 "rad"/s xx t)]V/mhatj`. If the wave falls normally on a perfectly reflecting surface having an area of 100 cm2. If the radiation pressure exerted by the E.M. wave on the surface during a 10-minute exposure is `x/10^9 N/m^2`. Find the value of x.


A plane electromagnetic wave travels in free space along the x-direction. The electric field component of the wave at a particular point of space and time is E = 6 Vm-1 along the y-direction. Its corresponding magnetic field component, B would be ______.


Sunlight falls normally on a surface of area 36 cm2 and exerts an average force of 7.2 × 10-9 N within a time period of 20 minutes. Considering a case of complete absorption the energy flux of incident light is ______.


The electric field in an electromagnetic wave is given by E = 56.5 sin ω(t - x/c)Nc-1. Find the intensity of the wave if it is propagating along x-axis in the free space.

(Given ε0 = 8.85 × 10-12 C2 N-1 m-2)


A plane electromagnetic wave with frequency of 30 MHz travels in free space. At particular point in space and time, electric field is 6 V/m. The magnetic field at this point will be x × 10-8 T. The value of x is ______.


An electromagnetic wave of frequency 3 GHz enters a dielectric medium of relative electric permittivity 2.25 from vacuum. The wavelength of this wave in that medium will be ______ × 10-2 cm. 


A 27 mW laser beam has a cross-sectional area of 10 mm2. The magnitude of the maximum electric field in this electromagnetic wave is given by:

[Given permittivity of space ∈0 = 9 × 10-12 SI units, Speed of light c = 3  108 m/s] 


An electromagnetic wave of frequency v = 3.0 MHz passes from vacuum into a dielectric medium with permittivity ∈ = 4.0. Then ______.


Name the electromagnetic wave/radiation which is used to study crystal structure.


Share
Notifications



      Forgot password?
Use app×