MCQ
A motor starter
- AIs a variable resistor
- BOffsets the back $emf$ variations
- CHelps start a $DC$ motor
- ✓All of these
✓
Answer
Correct option: D.
All of these
d
(d)
(d)
starting resisted are used in high power $D)$ ( motes, before we had variable frequent $A C$ motor drive, high power $D C$ motors were compos. Starting ngistors are used to limit starting cessent. Therefore they of sets back emt mosiations so answer is all of these.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
The volume charge density of a sphere of radius $6 \,m$ is $2 \,\mu cm ^{-3}$. The number of lines of force per unit surface area coming out from the surface of the sphere is $....\times 10^{10}\, NC ^{-1}$. [Given : Permittivity of vacuum $\left.\epsilon_{0}=8.85 \times 10^{-12} C ^{2} N ^{-1}- m ^{-2}\right]$
→An electron and a proton enter a magnetic field perpendicularly. Both have same kinetic energy. Which of the following is true
A solid hemisphere of weight $P$ rests with its curved surface in contact with a rough inclined plane. A weight $Q$ is placed at some point on the rim of the hemisphere to keep its plane surface horizontal then its minimum coefficient of friction is
→A free electron of $2.6\, {eV}$ energy collides with a ${H}^{+}$ ion. This results in the formation of a hydrogen atom in the first excited state and a photon is released. Find the frequency of the emitted photon. $\left({h}=6.6 \times 10^{-34}\, {J} {s}\right)$
→A power transformer (step up) with an $1 : 8$ turn ratio has $60\, Hz, 120\, V$ across the primary; the load in the secondary is $10^4\ \Omega$. The current in the secondary is :-
→When a point source of monochromatic light is at a distance of $0.2 \ m$ from a photoelectric cell, the cut-off voltage and the saturation current are $0.6$ volt and $18 \ mA$ respectively. If the same source is placed $0.6\ m$ away from the photoelectric cell, then
→The current voltage relation of a diode is given by $I=(e^{1000V/T} -1)mA$ where the applied voltage $V$ is in volts and the temperature $T$ is in degree kelvin. If a student makes an error measuring $±0.01\ V$ while measuring the current of $5\ mA$ at $300\ K$, what will be the error in the value of current in $mA?$
→Two balls with same mass and initial velocity, are projected at different angles in such a way that maximum height reached by first ball is 8 times higher than that of the second ball. $T_{1}$ and $T_{2}$ are the total flying times of first and second ball, respectively, then the ratio of $T_{1}$ and $T_{2}$ is :
→In a step-up transformer, turn ratio is $8 : 1$. A $60\,Hz, 120\, volt$ input is connected with its primary coil. Load resistance in secondary coil is $10^4\,\Omega $ Find current in secondry coil.
→A particle with charge $q$, moving with a momentum $p$, enters a uniform magnetic field normally. The magnetic field has magnitude $B$ and is confined to a region of width $d$, where $d < \frac{p}{{Bq}}$, The particle is deflected by an angle $\theta $ in crossing the field
→