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nevsk [136]
3 years ago
9

Vector A extends from the origin to a point having polar coordinates (7, 70ᵒ ) and vector B extends from the origin to a point h

aving polar coordinates (4, 130ᵒ ). Find A · B.
Engineering
1 answer:
yaroslaw [1]3 years ago
8 0

Answer:

13.95

Explanation:

Given :

Vector A polar coordinates = ( 7, 70° )

Vector B polar coordinates = ( 4, 130° )

To find A . B we  will

A ( r , ∅ ) = ( 7, 70 )

A = rcos∅ + rsin∅

therefore ; A  = 2.394i + 6.57j

B ( r , ∅ ) = ( 4, 130° )

B = rcos∅ + rsin∅

therefore ;  B = -2.57i + 3.06j

Hence ; A .B

( 2.394 i + 6.57j ) . ( -2.57 + 3.06j ) = 13.95

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Answer:

The given blanks can be filled as given below

Voltmeter must be connected in parallel

Explanation:

A voltmeter is connected in parallel to measure the voltage drop across a resistor this is because in parallel connection, current is divided in each parallel branch and voltage remains same in parallel connections.

Therefore, in order to measure the same voltage across the voltmeter as that of the voltage drop across resistor, voltmeter must be connected in parallel.

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An inductor is energized as in the circuit of Fig. 2-4a. The circuit has L 10 mH and VCC 14 V. (a) Determine the required on tim
Savatey [412]

Answer:

A) 11.1 ms

B) 5.62 Ω

Explanation:

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i = \sqrt{\frac{2W}{L} }   ----- ( 1 )

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Input values into equation 1  

i = 15.49 A

Now determine the time required  with expression below

i( t ) = 15.49 A

L = 10 mH, Vcc = 14

hence the time required ( T-on ) = 11.1 ms

attached below is detailed solution

B) <u>select the value of R such that switching cycle can be repeated every 20 ms </u>

using the expression below

τ = \frac{L}{R}  ---- ( 2 )

but first we will determine the value of τ

τ = t-off / 5 time constants

  = (20 - 11.1 ) / 5  = 1.78 ms

Back to equation 2

R = L / τ

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  = 5.62 Ω

3 0
3 years ago
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aliina [53]

Answer and Explanation:

Pyroelectric material

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The potential difference generated is for very less time

The generation of potential difference is due to change in position of atoms after heating or cooling.

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