The forming section of a plastics plant puts out a continuous sheet of plastic that is 1.2 m wide and 2 mm thick at a rate of 15
m/min. The temperature of the plastic sheet is 908C when it is exposed to the surrounding air, and the sheet is subjected to air flow at 308C at a velocity of 3 m/s on both sides along its surfaces normal to the direction of motion of the sheet. The width of the air cooling section is such that a fixed point on the plastic sheet passes through that section in 2 s. Determine the rate of heat transfer from the plastic sheet to the air.
1 answer:
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Answer:
The given grammar is :
S = T V ;
V = C X
X = , V | ε
T = float | double
C = z | w
1.
Nullable variables are the variables which generate ε ( epsilon ) after one or more steps.
From the given grammar,
Nullable variable is X as it generates ε ( epsilon ) in the production rule : X -> ε.
No other variables generate variable X or ε.
So, only variable X is nullable.
2.
First of nullable variable X is First (X ) = , and ε (epsilon).
L.H.S.
The first of other varibles are :
First (S) = {float, double }
First (T) = {float, double }
First (V) = {z, w}
First (C) = {z, w}
R.H.S.
First (T V ; ) = {float, double }
First ( C X ) = {z, w}
First (, V) = ,
First ( ε ) = ε
First (float) = float
First (double) = double
First (z) = z
First (w) = w
3.
Follow of nullable variable X is Follow (V).
Follow (S) = $
Follow (T) = {z, w}
Follow (V) = ;
Follow (X) = Follow (V) = ;
Follow (C) = , and ;
Explanation:
Answer:
Diode equation for reverse saturation current
Voltage at which diode goes into Resistive region:V=-5 volts
Voltage at which high level injection occurs:Va=0.55 volt
Voltage at which avalanche multiplication occurs:V=5volts
Explanation:
we take here forward and reverse 0.7 volt and -5 volt
As Diode current equation is express as
....................1
here is total current through the diode and
is reverse saturated current and
is voltage drop across diode and
is idealized factor and
is thermal voltage
so here we know that when Bios is forward than
=
.................2
ans Bios is Reverse than
=
..................3
so here
1. diode reverse saturation current is express as
and
2. Voltage at which diode go into Reverse behavior will be
=
= -5 volt
and
3. voltage at which high level injection occur that is
Va = 0.55 volt
and
4. voltage at which avalanche multiplication occurs is
Va = 5 volt