The original temperature of a black body is 727⁰C. The temperature at which this black body must be raised so as to double the total radiant energy is
Options
(a) 971 K (b) 1190 […]
The length of an elastic string is a metre when the longitudinal tension is 4N and b metre when the longitudinal tension is 5N. The length of the string on metre when the longitudinal tension […]
When two small bubbles join to form a bigger one, energy is
Options
(a) Released (b) Absorbed (c) both (a) and (b) (d) None of these
Correct Answer:
Released
Explanation:
No explanation available. Be […]
Oil spreads over the surface of water where as water does not spread over the surface of the oil because
Options
(a) Surface tension of water is very high (b) Surface tension of water […]
In a capillary tube water raises by 1.2 mm. The height of water that will rise in another capillary tube having half the radius of the first will be
Options
(a) 1.2 mm (b) […]
A fluid is in streamline flow across a horizontal pipe of variable area of cross section. For this which of the following statements is correct?
Options
(a) The velocity is minimum at the narrowest […]
If liquid level falls in a capillary then radius of capillary will be
Options
(a) Smaller (b) Greater (c) Same (d) None of these
Correct Answer:
Greater
Explanation:
No explanation available. Be the first […]
The wetability of a surface by a liquid depends primarily on
Options
(a) surface tension (b) density (c) angle of contact between the surface and the liquid (d) viscosity
Correct Answer:
angle of contact […]
The pressure at the bottom of a tank containing a liquid does not depend on
Options
(a) Acceleration due to gravity (b) Height of liquid column (c) Area of bottom surface (d) Nature of […]
A body, which emits radiations of all possible wavelengths, is known as
Options
(a) Good conductor (b) Partial radiator (c) Absorber of photons (d) Perfect black body
Correct Answer:
Perfect black body
Explanation:
No […]
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