In the illustration, if the device in figure "A" has a step-up ratio of 10 to 1, what voltage should be measured at the secondary shortly after the primary of the device is connected to 110 volts DC?
Answer-0 Volts (Because he is Talking About DC These type of Question is Just to Confuse You)
To prevent the race of a dc series motor what arrangement should make?
A.allways start at heavy load.
B.use a strong series-weak shunt compound dc motor.
C.use a weak series- strong shunt compound dc motor.
D. All of the above.
The armataure resistance of a 200 V d.c. machine has 0.5 ohm. If the full load armature current is 50 A, what will be the induced e.m.f. when, the machine acts as
(i) generator (ii) motor will be
(a) 230 V, 170 V
(b) 210 v, 190 v,
(c) 225 V, 175 C
(d)202.5 V, 197.5 V
Answer-C Because(e=v+ir gen, e=v-ir motor)
the winding resistance of a coil can be increased by___________the number of turns or using a _________wire.
Answer-Increase and Thinner Wire
A FUSE WILL BLOW FOR ALL OF THE LISTED REASON EXCEPT
1. excessive vibration
2. extremely hot surrounding
3. loose fuse clips
4. low contact resistance with the fuse
velocity & impedence of RLC circuit was found by ---------------vector
Answer-Adding the Phase Vector
What happens to the strength of electro magnetic field when current passing through an inductor is halfed ________
Fuses placed in series with a thermal trip = - type circuit breaker are used for
C.Short duration surge protection
D.Sustained overload protection