- ASilver
- BCopper
- CConstantan
- DGermanium
Explanation:
Alloys like constantan or manganin are used for making standard resistance coils due to their high resistivity values and very small temperature coefficient.
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Refractive index of glass is
and refractive index of water is
. If the speed of light in glass is 2.00
m/s, the speed in water will be
|
(a) 2.67 |
(b) 2.25 |
(c) 1.78 |
(d) 1.50 |
The working of dynamo is based on principle of
|
(a) Electromagnetic induction |
(b) Conversion of energy into electricity |
|
(c) Magnetic effects of current |
(d) Heating effects of current |
A far sighted man who has lost his spectacles, reads a book by looking through a small hole (3-4 mm) in a sheet of paper. The reason will be
|
(a) Because the hole produces an image of the letters at a longer distance |
|
(b) Because in doing so, the focal length of the eye lens is effectively increased |
|
(c) Because in doing so, the focal length of the eye lens is effectively decreased |
|
(d) None of these |
A signal emitted by an antenna from a certain point can be received at another point of the surface in the form of
|
(a) Sky wave |
(b) Ground wave |
(c) Sea wave |
(d) Both (a) and (b) |