The de-Broglie wavelength λ associated with an electron having kinetic energy E is given by the expression
|
(a) |
(b) |
(c) 2mhE |
(d) |
The de-Broglie wavelength λ associated with an electron having kinetic energy E is given by the expression
|
(a) |
(b) |
(c) 2mhE |
(d) |
(a)
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If the direction of the initial velocity of the charged particle is neither along nor perpendicular to that of the magnetic field, then the orbit will be
|
(a) A straight line |
(b) An ellipse |
(c) A circle |
(d) A helix |
If luminous efficiency of a lamp is 2 lumen/watt and its luminous intensity is 42 candela, then power of the lamp is
|
(a) 62 W |
(b) 76 W |
(c) 138 W |
(d) 264 W |
A motor having an armature of resistance 2Ω is designed to operate at 220 V mains. At full speed, it develops a back e.m.f. of 210V. When the motor is running at full speed, the current in the armature is
|
(a) 5A |
(b) 105A |
(c) 110A |
(d) 215A |
Suppose a planet goes around Sun with a linear speed twice as fast that of earth. What will be it's orbit size as compared to that of earth ? (Radius of earth = R)
|
(a) R / 4 |
(b) R / 2 |
(c) R |
(d) 2R |
The refractive index of a certain glass is 1.5 for light whose wavelength in vacuum is 6000 Å. The wavelength of this light when it passes through glass is
|
(a) 4000 Å |
(b) 6000 Å |
(c) 9000 Å |
(d) 15000 Å |