- A50MHz
- B40MHz
- C30MHz
- D20MHz
Explanation:
The ionosphere can reflect electromagnetic waves of frequency less than 40MHz but not of frequency more than 40MHz.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
The large scale destruction, that would be caused due to the use of nuclear weapons is called
|
(a) Nuclear holocaust |
(b) Thermo-nuclear reaction |
|
(c) Nuetron reproduction factor |
(d) None of these |
The hottest planet of solar system is
|
(a) Mars |
(b) Mercury |
(c) Venus |
(d) Pluto |
Four charges are placed on corners of a square as shown in figure having side of 5cm. If Q is one microcoulomb, then electric field intensity at centre will be
|
(a) 1.02 |
(b) 2.04 |
|
(c) 2.04 |
(d) 1.02 |
What is the effect on Fresnel’s biprism experiment when the use of white light is made
|
(a) Fringe are affected |
|
(b) Diffraction pattern is spread more |
|
(c) Central fringe is white and all are coloured |
|
(d) None of these |