Answer:
The resistance of the tungsten coil at 80 degrees Celsius is 15.12 ohm
Explanation:
The given parameters are;
The resistance of the tungsten coil at 15 degrees Celsius = 12 ohm
The temperature coefficient of resistance of tungsten = 0.004/°C
The resistance of the tungsten coil at 80 degrees Celsius is found using the following relation;
R₂ = R₁·[1 + α·(t₂ - t₁)]
Where;
R₁ = The resistance at the initial temperature = 12 ohm
R₂ = The resistance of tungsten at the final temperature
t₁ = The initial temperature = 15 degrees Celsius
t₂ = The final temperature = 80 degrees Celsius
α = temperature coefficient of resistance of tungsten = 0.004/°C
Therefore, we have;
R₂ = 12×[1 + 0.004×(80 - 15)] = 15.12 ohm
The resistance of the tungsten coil at 80 degrees Celsius = 15.12 ohm.
Groups
Same number of valence electrons
Li, Na, K
Explanation:
A.
If the periodic table is not color coded, the groups of elements gives the arrangement of atoms with the same chemical properties.
All elements that are in the same group have the same chemical properties.
Periodic table groups are also called family. They are the vertical columns on the periodic table.
B.
Elements that same number of electrons in outermost shell have the same chemical properties.
The outermost shell is called the valence shell of an atom.
They are the shell containing the most loosely held electrons. Group 1 has just one electron in their outermost shell.
C.
Li Na k group 1
F Cl Br group 7
learn more:
Periodic table brainly.com/question/2014634
Groups brainly.com/question/2690837
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Answer:
60 J
Explanation:
Given That
Coefficient of performance, CoP = 4.2
Quantity of heat of the refrigerator, Q = 250 J
Work done by the refrigerator, W = ?
First, it should be noted that the Coefficient of Performance can be said to be, the ratio of the Heat required to the Work done by the system. Mathematically written as,
CoP = Q / W
Since we are already given the values from our question, we can plug it in as it's a pretty straightforward question
4.2 = 250 / W, making W subject of formula, we have
W = 250 / 4.2
W = 60J
Thus, the Work done by the refrigerator is 60 J
The answer is a
Hope this helps!
