The frequency of y-rays, X-rays and ultraviolet rays are a, b and c respectively. Then
a > b > c
a < b < c
a = b = c
a > c > b
The structure of solids is investigated by using
cosmic rays
X-rays
y-rays
infrared radiations
Which of the following is the longest wave?
Microwaves
Radiowaves
A signal emitted by an antenna from a certain point can be received at another point of the surface in the form of
sky wave
ground wave
sea wave
both (a) and (b)
In a certain region of space electric file and magnetic field are perpendicular to each other and an electron enters in region perpendicular to the direction of and both and moves undeflected, then velocity of electron is
A TV tower has a height of 100 m. How much population is covered by the TV broadcast if the average population density around the tower is 1000 km-2 (radius of earth = 6370 km)?
4 lakh
40,000
4000
40 lakh
The charging current for a capacitor at any instant is 0.25 A.The displacement current across the capacitor plates at that instant is
0.5 A
0.25 A
2.5 A
1 A
The frequency of electromagnetic wave, which is best suited to observe a particle of radius 3 × 10-4 cm, is of the order of
1015
1014
1013
1012
The amplitudes of electric and magnetic fields in an electromagnetic wave are related to each other as
E0 = B0
E0 = cB0
E0 = B0 /c
E0 = c/B
Which of the following has minimum wavelength?
Ultraviolet rays
Cosmic rays
