Aptitude Test Problems in Physics Science for Everyone by S Krotov ( PDFDrive.com )

Fig. 224

The induced emf is now 152 = anti. Thus, for the
internal resistance of the motor, we obtain

r — (W —al's) cc

mg

For the maximum liberated power, we can write

(W—I') — migui ,

where it can easily be shown that the maximum

power Z' = al/ is liberated under the condition

11' = 15/2 (the maximum value of the denomi-

nator). Hence

If v 1

= 2cc =

= 2 m/s,

mv 2

m'— 2

Oh va)

—10 T e 6.7 kg.

—

3.58. Let us plot the time dependences Ue, (t)

of the external voltage, / 0 (t) of the current in the

circuit (which passes only in one direction when

the diode is open), the voltage across the capacitor

U 0 (t), and the voltage across the diode U a (t)

(Fig. 225).

Therefore, the voltage between the anode and

the cathode varies between 0 and —2 U 0.

3.59. Since the current and the voltage vary in

phase, and the amplitude of current is I =