Which of the following, is the longest wave ? [1989]
Pick out the longest wavelength from the following types of radiation. [1990]
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The frequency of electromagnetic wave, whichis best suited to observe a particle of radius3 × 10–4 cm is of the order of [1991]
The structure of solids is investigated by using [1992]
A signal emitted by an antenna from a certainpoint can be received at another point of thesurface in the form of [1993]
The oscillating electric and magnetic field vectorsof electromagnetic wave are oriented along [1994]
Which one of the following electromagneticradiations has the smallest wavelength? [1994]
If ∈0 and μ0 are the electric permittivity and magnetic permeability in vacuum, ∈ and μ are corresponding quantities in medium, then refractive index of the medium is [1997]
In a circuit, inductance L and capacitance C are connected as shown in the figure. A1 and A2
are ammeters. When key K is pressed to complete the circuit, then just after closing key (K), the readings of A1 and A2 will be [1999]
The electromagnetic radiations are caused by [1999]
The frequencies of X-rays, γ-rays and ultravioletrays are respectively a, b, and c. Then [2000]
Which of the following is positively charged? [2001]
if represent electric and magnetic field vectors of the electromagnetic waves, then the direction of propagation of the waves will be along
Which of the following electromagneticradiations has the least wavelength? [2002]
Green-house effect is the heating up of earth's atmosphere due to [2002]
Which one of the following rays is notelectromagnetic wave ? [2003]
We consider the radiation emitted by the humanbody. Which of the following statements is true? [2003]
If λv, λx and λm represent the wavelengths of visible light, X–rays and microwaves respectively, then
The electric and magnetic field of an electromagneticwave are [2007]
The velocity of electromagnetic radiation in a medium of permittivity ∈0 and permeability μ0 is given by [2008]
The electric field part of an electromagnetic wave in a medium is represented by Ex=0;
Ez = 0. The wave is : [2009]
Which of the following statement is false for theproperties of electromagnetic waves? [2010]
The electric and the magnetic field associated with an E.M. wave, propagating along the +z-axis, can be represented by [2011]
The decreasing order of wavelength of infrared,microwave, ultraviolet and gamma rays is [2011]
The electric field associated with an e.m. wave in vacuum is given by cos (kz – 6 ×108t), where E, z and t are in volt/m, meter and seconds respectively. The value of wave vector k is : [2012]
The ratio of amplitude of magnetic field to theamplitude of electric field for an electromagneticwave propagating in vacuum is equal to : [2012M]
An electromagnetic wave of frequency v = 3.0MHz passes from vacuum into a dielectricmedium with relative permittivity ε = 4.0. Then[NEET Kar. 2013]
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