The <em>mechanical advantage</em> of a machine determines its "usefulness." <em>(C)
</em>
B. They came up with the term “radioactivity.”
C. They conducted experiments with uranium-containing minerals and pure uranium.
E. They discovered two new radioactive elements
I’m prettier sure the answer is b cuz it’s not the core ok that
Answer:
Current in resistors = 1.5 amp
Current in resistors = 0.18 amp
P = 93.75 watts
Explanation:
Given:
1. Three 5 ohm resistor(series)
Voltage = 10 volt
2. Three 5 ohm resistor(parallel)
Voltage = 9 volt
3. Three 5 ohm resistor(series)
Voltage = 6 volt
Find:
Current in resistors
Current in resistors
Total power of circuit
Computation:
1. Total resistor (Series) R = R1 + R2 + R3
Total resistor (Series) R = 5 + 5 + 5
Total resistor (Series) R = 15 ohm
I = V/R
Current in resistors = (15)/(10)
Current in resistors = 1.5 amp
2. Total resistor (Series) R = 1/[1/R1 + 1/R2 + 1/R3
Total resistor (Series) R = 1[1/5 + 1/5 + 1/5]
Total resistor (Series) R = 1.67 ohm
I = V/R
Current in resistors = (1.67)/(9)
Current in resistors = 0.18 amp
3. Total resistor (Series) R = R1 + R2 + R3
Total resistor (Series) R = 5 + 5 + 5
Total resistor (Series) R = 15 ohm
I = V/R
I = (15)/(6)
I = 2.5 amp
P = I²(R)
P = (2.5)²(15)
P = 93.75 watts
The reactance of an inductor is given by:
X = 2πfL
X is the inductor's reactance
f is the frequency of the supplied voltage
L is the inductor's inductance
The given values are:
f = 60.0Hz
L = 43.8mH (I'm assuming the value is given in milli Henries because this is within the normal range of inductors)
Plug these values in and solve for X:
X = 2π(60.0)(43.8×10⁻³)
X = 16.512Ω
Round this value to 3 significant figures:
X = 16.5Ω
The relationship between AC voltage and current is given by:
V = IZ
V is the voltage
I is the current
Z is the impedance
For an AC inductor circuit, Z = X = 16.512Ω and V is the rms voltage 120V. Plug these values in to get the rms current:
120 = I×16.512
I = 7.2673A
Round this value to 3 significant figures:
I = 7.27A