At two places A and B using vibration magnetometer, a magnet vibrates in a horizontal plane and its respective periodic time are 2 sec and 3 sec and at these places the earth's horizontal components are HA and HB respectively. Then the ratio between HA and HB will be
| (a) 9 : 4 | (b) 3 : 2 | (c) 4 : 9 | (d) 2 : 3 |
(a) 9 : 4
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Source of Sun's energy is
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(a) Burning of hydrogen |
(b) Fission reactions involving hydrogen |
|
(c) Fusion reactions involving hydrogen |
(d) Some other source |
In nuclear reaction 
A denotes
|
(a) Electron |
(b) Positron |
(c) Proton |
(d) Neutron |
Our eye is most sensitive for which of the following wavelength
|
(a) 4500 Å |
|
(b) 5500 Å |
|
(c) 6500 Å |
|
(d) Equally sensitive for all wave lengths of visible spectrum |
Cathode rays are similar to visible light rays in that
|
(a) They both can be deflected by electric and magnetic fields |
|
(b) They both have a definite magnitude of wavelength |
|
(b) They both have a definite magnitude of wavelength |
|
(d) They both can expose a photographic plate |
The kinetic energy of an electron with de-Broglie wavelength of 0.3 nanometer is
|
(a) 0.168 eV |
(b) 16.8 eV |
(c) 1.68 eV |
(d) 2.5 eV |
When the distance between the charged particles is halved, the force between them becomes
|
(a) One-fourth |
(b) Half |
(c) Double |
(d) Four times |
When a resistor of 11 W is connected in series with an electric cell, the current flowing in it is 0.5 A. Instead, when a resistor of 5 W is connected to the same electric cell in series, the current increases by 0.4 A. The internal resistance of the cell is
|
(a) 1.5 W |
(b) 2 W |
(c) 2.5 W |
(d) 3.5 W |