Answer: Rc = 400 Ω and Rb = 57.2 kΩ
Explanation:
Given that;
VCE = 5V
VCC = 15 V
iC = 25 mA
β = 100
VD₀ = 0.7 V
taking a look at the image; at loop 1
-VCC + (i × Rc) + VCE = 0
we substitute
-15 + ( 25 × Rc) + 5 = 0
25Rc = 10
Rc = 10 / 25
Rc = 0.4 k
Rc = 0.4 × 1000
Rc = 400 Ω
iC = βib
25mA = 100(ib)
ib = 25 mA / 100
ib = 0.25 mA
ib = 0.25 × 1000
ib = 250 μAmp
Now at Loop 2
-Vcc + (ib×Rb) + VD₀ = 0
-15 (250 × Rb) + 0.7 = 0
250Rb = 15 - 0.7
250Rb = 14.3
Rb = 14.3 / 250
Rb = 0.0572 μ
Rb = 0.0572 × 1000
Rb = 57.2 kΩ
Therefore Rc = 400 Ω and Rb = 57.2 kΩ
Answer:
(C) 29°
Explanation:
ACME THREAD ANGLE : it is the angle measured between the thread axis and thread the thread flanks, with the help of thread angle we calculate the shape of screw thread it is the mean of v thread and square thread the acme thread angle is denoted by β every thread has its own charactersistics which depends on the pitch and diameter of the thread
Answer:
W = - 184.8 kW
Explanation:
Given data:
We know that work is done as
![W = - [ Q + \dor m[h_2 - h_1]]](https://tex.z-dn.net/?f=W%20%3D%20-%20%5B%20Q%20%2B%20%5Cdor%20m%5Bh_2%20-%20h_1%5D%5D)
for
density of air is 1.22 kg/m^3 and 
for 
W = -[14 + 1.708[400-300]]
W = - 184.8 kW
Fine grained of alkali igneous rocks cannot be used in cement because of the volume expansion caused by the Alkali-silica reaction, fine-grained igneous rocks cannot be used as aggregates in cement.
<h3>What does fine grained mean in an igneous rock?</h3>
Extrusive igneous rocks have a fine-grained or aphanitic texture, with grains that are too small to see without a magnifying glass. The fine-grained texture suggests that the rapidly cooling lava did not have enough time to form large crystals. A petrographic microscope can be used to examine these tiny crystals.
The texture of an igneous rock (fine-grained vs coarse-grained) is determined by the rate at which the melt cools: slow cooling produces large crystals, while fast cooling produces small crystals.
The chemical reaction that occurs in both alkali cations and hydroxyl ions in the pore solution of hydrated cement paste and certain reactive silica phases present in concrete aggregates is known as the alkali-silica reaction (ASR).
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Answer:
i think its A. increasing research to find alternative natural resources for the future
