Related Questions

The emissivity of a polished silver body is _________ as compared to black body.
A Same
B Low
C Very low
D High
Emissivity of a white polished body in comparison to a black body is
A Higher
B Lower
C Same
D Depends upon the shape of body
A certain dentist specializes in implanting gold and silver teeth in his patients mouths .He charges $ 650 for a gold tooth an $ 325. for a silver tooth. If his told fees for implanting gold and silver teeth last week were $ 15, 925 in total and he implanted five more gold teeth that silver teeth, how many teeth in total did he implant over the week?
A 33
B 32
C 31
D 34
In a city 40% of the people have black hair, 25% have black eyes and 10% have both black hair and black eyes. What percentage of the people in the city has neither black hair nor black eyes?
A 35
B 40
C 45
D 50
In a certain city 40% of the people have black hair, 25% have black eyes and 10% have both black hair and black eyes. What percentage of the people in the city have neither black hair nor black eyes?
A 35
B 40
C 45
D 50
While the total emissivity of a perfect black body is unity, the same for a real body is
A 0
B 1
C > 1
D Between 0 and 1
In a rare coin collection, all coins are either pure gold or pure silver , and there is initially one gold coin for every three silver coins . With the addition of 10 more gold coins to the collection, the ratio of gold coins to silver coins is 1 to 2. Based on this information , how many total coins are there now in this collection (after the acquisition)?
A 40
B 50
C 70
D 90
The emissivity for a black body is
A 0
B 0.5
C 0.75
D 1
What is the emissivity of a black body?
A 1
B 0
C 0.90
D 0.5
In thermal radiation for a black body (where, ε is emissivity and α is absorptivity)
A α = 1; ε ≠ 1
B α ≠ 1, ε = 1
C α ≠ 1, ε ≠ 1
D α = 1; ε = 1

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