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### If a spring of spring constant k stretched by a length x under tension T, the energy

If a spring of spring constant k stretched by a length x under tension T, the energy stored is

Options

(a) 2k/T² (b) 2T²/k (c) T²/2k (d) 2T/k²

T²/2k

Explanation:

Energy stored […]

### Three objects coloured black, gray and white can withstand hostile conditions upto 2800⁰C.

Three objects coloured black, gray and white can withstand hostile conditions upto 2800⁰C. These objects are thrown into a furnace where each of them attains a temperature of 2000⁰C. Which object will glow brightest?

### A body of mass 120 kg and density 600 kg/m³ floats in water.

A body of mass 120 kg and density 600 kg/m³ floats in water. What additional mass could be added to the body so that the body will just sink?

Options

(a) 20 kg (b) […]

### If h is the height of the capillary rise and r be the radius of capillary tube,

If h is the height of the capillary rise and r be the radius of capillary tube, then which of the following relation will be correct?

Options

(a) hr=constant (b) h/r²=constant (c) hr²=constant (d) […]

### Ice is wrapped in black and white cloth. In which cases more ice will melt

Ice is wrapped in black and white cloth. In which cases more ice will melt

Options

(a) White (b) Black (c) In both cases equal amount will melt (d) None of these

### ln a surrounding medium of temperature 10⁰C a body takes 7 min for a fall

ln a surrounding medium of temperature 10⁰C a body takes 7 min for a fall of temperature from 60⁰C to 40⁰C. In what time the temperature of the body will fall from 40⁰C to 28⁰C? […]

### When the temperature increases, the viscocity of

When the temperature increases, the viscocity of

Options

(a) Gases decreases and liquid increases (b) Gases increases and liquids decreases (c) Gases and liquids increases (d) Gases and liquids decreases

Gases increases […]

### In which of the following heat loss is primarily not due to convection?

In which of the following heat loss is primarily not due to convection?

Options

(a) boiling of water (b) land and sea breeze (c) heating of glass surface of a bulb due to current […]

### Angle of contact of a liquid with a solid depends on

Angle of contact of a liquid with a solid depends on

Options

(a) Solid only (b) Liquid only (c) Both on solid and liquid only (d) Orientation of the solid surface in liquid

Correct […]

### A spherical body of emissivity e=0.6, placed inside a perfectly black body is maintained

A spherical body of emissivity e=0.6, placed inside a perfectly black body is maintained at temperature T then the energy radiated per second will be

Options

(a) E=0.4 eAT⁴ (b) E=0.8 eAT⁴ (c) E=0.6 […]

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