The velocity of electromagnetic wave is along the direction of
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
1 A
2.5 A
The frequency of y-rays, X-rays and ultraviolet rays are a, b and c respectively. Then
a>b>c
a
a=b-c
a>c>b
If a source is transmitting electromagnetic waves of frequency 8.2 × 106 Hz, then wavelength of the electromagnetic waves transmitted from the source will be
40.5m
42.3m
36.6m
50.9m
Which of the following rays are not electromagnetic waves?
β-rays
Heat rays
X-rays
Y-rays
Which of the following is the longest wave?
x-rays
y-rays
Microwaves
Radiowaves
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)?
4,00,000
4,000
40,000
40,000,00
Which of the following has minimum wavelength?
Ultraviolet rays
Cosmic rays
What is the cause of "Green house effect"?
Infra red rays
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
