Answer:
R= 20 ohm
Explanation:
Given that
Current ,I = 6 A
Voltage difference ,ΔV = 120 V
Lets take resistance of the stem iron = R
We know that ,the relationship between current ,voltage difference and resistance is given as
ΔV = I R
Now by putting the values in the above equation we get
R= 20 ohm
Therefore the resistance of the steam will be 20 ohm.
The following information are given in the question:
Mass, M = 8 g
Temperature, T = 20 degree Celsius
Specific heat of water [this value is a constant] C = 1 c/gc
Heat, Q = ?
The formula for calculating the amount of heat required is given below:
Q = MCT = 8 * 1 * 20 = 160
Therefore, Q = 160 cal.
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Emissivityis a measure of how much thermal radiation a body emits to its environment. On the other hand we have that reflectivity is a measure of how much is reflected, and transmissivity is a measure of how much passes through the object. If a body is required to be ideally reflective to its maximum efficiency, the body should NOT have the property of transmissivity or emissivity. Therefore it should be 0 its emittivity.
Correct answer would be A : ZERO.
