With the increase in principle quantum number, the energy difference between the two successive energy levels
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(a) Increases |
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(b) Decreases |
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(c) Remains constant |
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(d) Sometimes increases and sometimes decreases |
(b) Decreases
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Dual nature of radiation is shown by
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(a) Diffraction and reflection |
(b) Refraction and diffraction |
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(c) Photoelectric effect alone |
(d) Photoelectric effect and diffraction |
In general, metallic ropes are suspended on the carriers which take inflammable material. The reason is
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(a) There speed is controlled |
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(b) To keep the centre of gravity of the carrier nearer to the earth |
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(c) To keep the body of the carrier in contact with the earth |
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(d) Nothing should be placed under the carrier |
Two uniform wires A and B are of the same metal and have equal masses. The radius of wire A is twice that of wire B. The total resistance of A and B when connected in parallel is
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(a) 4 Ω when the resistance of wire A is 4.25 Ω |
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(b) 5 Ω when the resistance of wire A is 4.25 Ω |
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(c) 4 Ω when the resistance of wire B is 4.25 Ω |
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(d) 4 Ω when the resistance of wire B is 4.25 Ω |
Boron rods in nuclear reactor are used as a
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(a) Moderator |
(b) Control rods |
(c) Coolants |
(d) Protective shield |
The magnetic field due to the earth is closely equivalent to that due to
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(a) A large magnet of length equal to the diameter of the earth |
| (b) A magnetic dipole placed at the centre of the earth |
| (c) A large coil carrying current |
| (d) Neither of the above |
If V be the accelerating voltage, then the maximum frequency of continuous X-rays is given by
(a) 
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(b) 
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(c)
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(d) 
|