If it is. DC, direct current reverse the polarity of power leads on the motor.
If it is a 3 phase ac alternating current, reverse any of the two of three leads.
Disconnect power before attempting.
convert 40db to standard gain
AL=10^40/20=100
calculate total voltage gain
=AL×RL/RL+Ri
=83.33
38.41 DB
calculate power
Pi=Vi^2/Ri Po=Vo^2/RL
power gain= Po/Pi
=13.90×10^6
Answer: 255
255 turns are required to create 25 ohms of secondary impedance.
Explanation:
Given that,
Number of turns in primary wire N₁ = 900
impedance on Primary wire Z₁ = 400 ohms
Number of turns in Secondary wire N₂ = ?
impedance on Secondary wire Z₂ = 25 ohms
we know that, the relationship between turn and impedance is
Zp / Zs = ( Np / Ns )²
(Primary impedance / secondary impedance) = Number of turns in primary wire / Number of turns in secondary wire)²
there fore
Z₁ / Z₂ = ( N₁ / N₂ )²
Now we substitute
( 400 / 25 ) = ( 900 / N₂ )²
400 / 25 = 900² / N₂²
we cross multiple to get our N₂
400 × N₂² = 900² × 25
N₂² = ( 900² × 25 ) / 400
N₂² = ( 810000 × 25 ) / 400
N₂² = 20250000 / 400
N₂² = 50625
N₂ = √50625
N₂ = 225
Therefore 255 turns are required to create 25 ohms of secondary impedance.
They do in fact heat up while receiving energy.