A source emits light of wavelength 4700Å, 5400 Å and 6500 Å. The light passes through red glass before being tested by a spectrometer. Which wavelength is seen in the spectrum
|
(a) 6500 Å |
(b) 5400 Å |
(c) 4700 Å |
(d) All the above |
(a) 6500 Å
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An object is immersed in a fluid. In order that the object becomes invisible, it should
|
(a) Behave as a perfect reflector |
|
(b) Absorb all light falling on it |
|
(c) Have refractive index one |
|
(d) Have refractive index exactly matching with that of the surrounding fluid |
Which of the following relation is correct in magnetism
|
(a) |
(b) I = V + H |
(c) |
(d) |
Unit of magnetic flux density (or magnetic induction) is
| (a) Tesla | (b) Weber/metre2 |
| (c) Newton/ampere-metre | (d) All of the above |
The mutual characteristic curves of a triode are as shown in figure. The cut off voltage for the triode is
| (a) 0 V | (b) 2 V | (c) – 4 V | (d) 6 V |
The refractive index of a piece of transparent quartz is the greatest for
|
(a) Red light |
(b) Violet light |
(c) Green light |
(d) Yellow light |
The Lyman series of hydrogen spectrum lies in the region
|
(a) Infrared |
(b) Visible |
(c) Ultraviolet |
(d) Of X - rays |
For protecting a sensitive equipment from the external magnetic field, it should be
|
(a) Placed inside an aluminium cane |
|
(b) Placed inside an iron cane |
|
(c) Wrapped with insulation around it when passing current through it |
|
(d) Surrounded with fine copper sheet |
