Answer:
A
Explanation:
blue stars have a hotter sufarce arra, thats what makes them brighter.
The answer is B. It is measured in amperes.
Answer:
water evaporates into the atmosphere
R = 10 ohm
I = 5 A
V= IR = 10 x 5 = 50 v
Answer:
I will specify a value of 0.009T for the alternator’s magnetic field
Explanation:
E_peak = 14 V
d = 10cm = 0.1m, so r = 0.1/2 =0.05m
N = 250 turns
f = 1200rpm = (1200rp/m x 1m/60sec) = 20 revolutions per second
At peak performance, peak voltage is given by the equation;
E_peak = NABω
Let's make the magnetic field B the subject;
B = E_peak/(NAω)
Now we know that ω = 2πf
Thus, ω = 2π x 20 revs/s = 125.664 revs/s.
Let's convert it to the standard unit which is rad/s.
1 rev/s = 6.283 rad/s
Thus, 125.664 revs/s = 125.664 x 6.283 = 789.55 rad/s
Area (A) = πr² = π x 0.05² = 0.007854 m²
Thus, plugging in the relevant values to get;
B = 14/[(250 x 0.007854 x 789.55)] = 0.009T
