A double charged lithium atom is equivalent to hydrogen whose atomic number is 3. The wavelength of required radiation for emitting electron from first to third Bohr orbit in 
will be (Ionisation energy of hydrogen atom is 13.6eV)
|
(a) 182.51 Å |
(b) 177.17 Å |
(c) 142.25 Å |
(d) 113.74 Å |
(d) 113.74 Å
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Two magnets of same size and mass make respectively 10 and 15 oscillations per minute at certain place. The ratio of their magnetic moments is
| (a) 4 : 9 | (b) 9 : 4 | (c) 2 : 3 | (d) 3 : 2 |
Choose the correct statement
|
(a) When we heat a semiconductor its resistance increases |
|
(b) When we heat a semiconductor its resistance decreases |
|
(c) When we cool a semiconductor to 0 K then it becomes super conductor |
|
(d) Resistance of a semiconductor is independent of temperature |
A charge of 1C is moving in a magnetic field of 0.5Tesla with a velocity of 10m/sec Perpendicular to the field. Force experienced is
|
(a) 5 N |
(b) 10 N |
(b) 10 N |
(d) 0 N |
All six capacitors shown are identical, Each can withstand maximum 200 volts between its terminals. The maximum voltage that can be safely applied between A and B is
|
(a) 1200 V |
(b) 400 V |
(c) 800 V |
(d) 200 V |
Number of spectral lines in hydrogen atom is
|
(a) 3 |
(b) 6 |
(c) 15 |
(d) Infinite |
Which is not true with respect to the cathode rays
|
(a) A stream of electrons |
(b) Charged particles |
|
(c) Move with speed same as that of light |
(d) Can be deflected by magnetic fields |
The binding energy per nucleon of deuterium and helium atom is 1.1 MeV and 7.0 MeV. If two deuterium nuclei fuse to form helium atom, the energy released is
|
(a) 19.2 MeV |
(b) 23.6 MeV |
(c) 26.9 MeV |
(d) 13.9 MeV |
In which of the following ionic bond is present
|
(a) NaCl |
(b) Ar |
(c) Si |
(d) Ge |