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3 years ago

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The leading cause of air pollution is?

1 answer:

stellarik [79]3 years ago

3 0

Combustion Engine Exhaust----Cars, trucks, jet airplanes and other combustion engine vehicles cause air pollution. The exhaust from these contains carbon monoxide, nitrous oxide and gaseous oxide. This type of air pollution creates smog

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In the formula used to solve problems related to the first law of thermodynamics, what does Q represent? A.internal energy

Blizzard [7]

B, heat, is the correct answer. Heat is represented by a capital q in thermodynamic equations.

7 0

3 years ago

Read 2 more answers

A magnetic field is perpendicular to the plane of a single-turn circular coil. The magnitude of the field is changing, so that a

scoundrel [369]

To solve this problem we will apply the concepts related to magnetic flux and induced voltage. This last expression understood as the variation of the magnetic flux over time and, in turn, the magnetic flux expressed as the variation of the magnetic field in a certain area.

Magnetic flux through the circular coil is given as

$\Phi_C = B(\pi r^2)$

The induced voltage is the change of the magnetic flux across the time, then

$\epsilon_{emf,C} = \frac{B(\pi r^2)}{t}$

At the same time the magnetic flux through the square coil would be given as,

$\Phi_S = B(r^2)$

And the induced voltage EMF will be

$\epsilon_{emf,s} = \frac{B(r^2)}{t}$

Equating both expression we have

$\epsilon_{emf,s} = \frac{\epsilon_{emf,C}tr^2}{\pi r^2t}$

$\epsilon_{emf,s} = \frac{0.74V}{\pi}$

$\epsilon_{emf,s} = 0.23355V$

Therefore the emf induced in the square coil is 0.23355V

7 0

3 years ago

A composite load consists of three loads connected in parallel. One draws 100 W at a PF of 0.92 lagging, another takes 250 W at

fenix001 [56]

Answer:

a) $I_{RMS} = 4.79 A$

b) $PF = 0.908$

Explanation:

Get the reactive powers for each of the loads:

Reactive power = Real Power * tanθ

For load 1

Active power, P₁ = 100 W

Power factor, $cos \theta_{1} = 0.92$

$\theta_{1} = cos^{-1} 0.92\\\theta_{1} = 23.074$

$Q_{1}= P_{1} tan \theta_{1} \\Q_{1}= 100tan 23.074\\Q_{1}= 42.60 W$

For load 2

Active power, P₂ = 250 W

Power factor, $cos \theta_{2} = 0.8$

$\theta_{2} = cos^{-1} 0.8\\\theta_{2} = 36.87$

$Q_{2}= P_{1} tan \theta_{2} \\Q_{2}= 250tan 36.87\\Q_{2}= 187.5 W$

For load 3

Active power, P₃ = 250 W

Power factor, $cos \theta_{3} = 1$

$\theta_{3} = cos^{-1} 1\\\theta_{3} =0$

$Q_{2}= P_{1} tan \theta_{3} \\Q_{3}= 150tan 0\\Q_{3}= 0 W$

Calculate the total reactive power, $Q_{net} = 42.6 + 187.5 + 0$

$Q_{net} = 230.1 W$

Calculate the total active power, $P_{net} = 100 + 250 + 150 = 500 W$

$S_{net} = P_{net} + Q_{net} \\S_{net} = 500 + j230.1$

$P_{net} = IVcos \theta_{net}$

$\theta_{net} = tan^{-1} \frac{230.1}{500} \\\theta_{net} = 24.712$

V = 115 $V_{rms}$

$500 = I_{RMS} * 115 cos 24.712\\I_{RMS} = 500/104.47\\ I_{RMS} = 4.79 A$

b) Power factor of the composite load is $cos\theta_{net}$

$\theta_{net} = 24.712\\PF = cos 24.712\\PF = 0.908$

4 0

3 years ago

All living things are made of one or more cells.<br> True<br> False

dimulka [17.4K]

False because their are single cell organisms

7 0

3 years ago

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Which of the following could be described as "Energy cannot be created or destroyed ,only converted into other forms"?

Kryger [21]

Answer:

C

Explanation:

This is right because that's how u describe it

5 0

3 years ago