Answer:
Explanation:
From the equation:
Power dissipated= square of voltage supplied by battery ÷ Resistance of the load
i.e P= V^2/R
It means that at constant voltage, the the power consumed is inversely related to the resistance. Therefore the 10W bulb which has a higher resistance will consume less power using the sufficiently excess power dissipated to glow brighter than the 250W bulb which has a low resistance. The power dissipated will partly be used to overcome this low resistance making less power available for heating up the 250W bulb .
The first one is the answer
Answer:
The value of heat transferred watt per foot length Q = 54.78 Watt per foot length.
Explanation:
Diameter of pipe = 2 in = 0.0508 m
Steam temperature
= 300 F = 422.04 K
Duct temperature
= 70 F = 294.26 K
Emmisivity of surface 1 = 0.79
Emmisivity of surface 2 = 0.276
Net emmisivity of both surfaces ∈ = 0.25
Stefan volazman constant
= 5.67 ×

Heat transfer per foot length is given by
Q = ∈
A (
) ------ (1)
Put all the values in equation (1) , we get
Q = 0.25 × 5.67 ×
× 3.14 × 0.0508 × 1 × (
)
Q = 54.78 Watt per foot.
This is the value of heat transferred watt per foot length.
Answer:
3.115×
meter
Explanation:
hall-petch constant for copper is given by
=25 MPa
k=0.12 for copper
now according to hall-petch equation
=
+
240=25+
D=3.115×
meter
so the grain diameter using the hall-petch equation=3.115×
meter