# A permanent magnet stepper motor with 8 poles in stator and 6 poles in rotor will have a step angle of

24 views
A permanent magnet stepper motor with 8 poles in stator and 6 poles in rotor will have a step angle of (a) 7.5° (b) 15° (c) 30° (d) 60°

A permanent magnet stepper motor with 8 poles in stator and 6 poles in rotor will have a step angle of 15°

## Related questions

An 1.8° step, 4 -phase stepper motor has 40 teeth on 8 poles of the stator. The number of rotor teeth for their rotor will be: (A) 40 (B) 50 (C) 100 (D) 80

A 3 stack stepper motor with 12 number of rotor teeth has a step angle of: (A) 12° (B) 8° (C) 24° (D) 10°

A three-phase, three-stack, variable reluctance step motor has 20 poles on each rotor and stator stack. The step angle of this step motor is  (A) 3o (B) 6o (C) 9o (D) 18o

The number of poles of 8/6 stepper motor can be :

The step angle of the stepper motor is 2.5°. If the stepping frequency is 3600 pulses per second, then the shaft speed will be   (a) 144 rps (b) 3600 rps (c) 25 rps (d) 2.5 rps

The armature resistance of a permanent magnet dc motor is 0.8 Ohm. At no load, the motor draws 1.5 A from a supply voltage of 25 V and runs at 1500 rpm. The efficiency of the motor while it is operating on load at 1500 rpm drawing a current of 3.5 A from the same source will be  (A) 48.0% (B) 57.1% (C) 59.2% (D) 88.8%

A 3-phase induction motor under locked rotor condition and with stator supply, induces (A) small voltage at slip frequency (B) large voltage at rotor frequency (C) zero voltage at zero frequency (D) large voltage at slip frequency

The following motor definitely has a permanent magnet rotor  (A) DC commutator motor (B) Brushless dc motor (C) Stepper motor (D) Reluctance motor

An electric motor in which both stator field and rotor rotates with same speed is called?

in a three-phase induction motor, the rotor field runs at the following speed with respect to the stator structure:

The amount of current flowing through a circuit with a 40 V source and 6.8 kΩ of resistance is equal to: A. 27.2 mA B. 59 mA C. 5.9 mA D. 590 mA

In a single-phase induction motor when the rotor is stationary and voltage is applied to the stator, then (A) the flux is constant (B) the flux first decreases and then increases in the same direction (C) the flux increases and decreases in the opposite direction with the same magnitude (D) current flows through the rotor

The rotor of a stepper motor has no   (a) Winding (b) Commutator (c) Brushes (d) All of the above

A centre zero ammeters connected in the rotor circuit of a 6-pole 50 Hz induction motor makes 30 oscillations in one minute. The rotor speed is

The number of poles in a phase induction motor at 50 Hz and running at 1500 rpm will be?

The rotor frequency for a 3-phase 6-pole, 1000 r.p.m. induction motor with a slip of 0.04 is (a) 2 Hz (b) 4 Hz (c) 6 Hz (d) 8 Hz

The stator mmf and rotor mmf of a 3-phase induction motor (A) are equal (B) rotate with slip speed (C) are opposite but rotate with synchronous speed (D) rotate with the same rotor speed

A three phase slip ring induction motor is fed from the rotor side with stator winding short circuited stator is: (1) Slip frequency (2) Supply frequency (3) Frequency corresponding to rotor speed (4) Zero

If the stator winding of a three-phase induction motor is delta connected, the rotor winding   (a) should be delta connected (b) should be star connected (c) should not be delta connected (d) may be delta or star connected

A 6-pole, 50Hz, 3-φ induction motor is running at 950 r.p.m. and has Cu loss of 5kW. The rotor input is (a) 10 kW (b) 95 kW (c) 100 kW (d) 9.5 kW

An 8-pole, 50Hz, three-phase induction motor is running at 705rpm and has a rotor copper loss of 5kW. Its rotor input is (A) 5.06 kW (B) 0.3 kW (C) 100 kW (D) 83.33 kW

The power input to the rotor of a 400V, 50 Hz 6 pole three phase induction motor is 20kW. The slip is 3%. The frequency of rotor currents is: (A) 1 Hz (B) 1.5 Hz (C) 2 Hz (D) 1 2 Hz

A 0.5 Hp, 6 pole wound rotor induction motor is excited by a 3 phase 60 Hz source. Calculate the frequency of the rotor current at standstill.  (A) 50 Hz (B) 30 Hz (C) 60 Hz (D) 120 Hz

For a 1.8o, 2-phase bipolar stepper motor, the stepping rate is 100 steps/second. The rotational speed of the motor in rpm is  (A) 15 (B) 30 (C) 60 (D) 90

An 8-pole alternator runs at 750 rpm and supplies power to a 6-pole induction motor which has a full load slip of 3 percent. The full load speed of the induction motor will be: A) 1000 rpm B) 920 rpm C) 950 rpm D) 970 rpm

A permanent magnet moving coil ammeter has a coil resistance of 99 ohm and Full Scale Deflection (FSD) current of 0.1mA. Shunt resistance is 1 ohm. Current through the meter at 0.5 F.S.D is:

A 400kW, 3 -phase, 440V, 50Hz induction motor has a speed of 950 rpm on full load. The machine has 6 poles. The value of slip for the machine will be (A) 0.06 (B) 0.10 (C) 0.04 (D) 0.05

A 3 phase, 400 volts, 50 Hz, 100 kW, 4 pole squirrel cage induction motor with a rated slip of 2% will have a rotor speed of: (A) 1500 rpm (B) 1470 rpm (C) 1530 rpm (D) 1570 rpm

An 8 pole wound rotor induction motor operating on 60 Hz supply is driven at 1800 r.p.m. by a prime mover in the opposite direction of revolving magnetic field. The frequency of the rotor current is (a) 30 Hz (b) 60 Hz (c) 120 Hz (d) 180 Hz

A neodymium magnet is a permanent magnet made from an alloy of _________ A) Neodymium and iron B) Neodymium, iron and iodine C) Neodymium and boron D) Neodymium, iron and boron

In wound rotor alternator, reactive power is maximum at a load angle of

If the supply frequency of a 3-phase induction motor is ‘f’, then frequency of rotor emf at motor slip ‘s’ will be   (a) sf (b) (1 – s)f (c) f/s (d) None of these

When the stator windings are connected in such a fashion that the number of poles are made half, the speed of the rotor of a synchronous motor?

The driving point impedance with poles at ω = 0(zero) and ω = ∞ (infinity) must have the  (a) s term in the denominator and an excess term in the numerator (b) s term in the numerator and an excess term in the denominator (c) s term in the numerator and equal number of terms in the numerator and denominator (d) s term in the denominator and equal number of terms in the numerator and denominator

The synchronous speed of an 8 pole induction motor supplied power from a 50 Hz source will be ?

The rotor impedance of a slip ring induction motor is (0.1 + j0.6)Ohm/ ph . The resistance/ph to be inserted into rotor to get maximum torque at starting should be

A rotating electrical machine its self-inductances of both the stator and the rotor windings, independent of the rotor position will be definitely not develop  (A) starting torque (B) synchronizing torque (C) hysteresis torque (D) reluctance torque

Two voltmeters of same range, one moving iron type and other permanent magnet moving coil type, are connected in parallel for measuring a.c. supply voltage. If the reading of MI type is 300V, the reading of PMMC type will be (a) zero (b) higher-than M.I. type (c) lower than M.I. type (d) same

In static Kramer drive, motor turns ratio is 0.6, the firing angle is 120o. The motor slip is   (a) 0.633 (b) 0.533 (c) 0.833 (d) 0.733

Which alternator will have more number of poles ? (a) coupled to steam turbine (b) coupled to gas turbine (c) coupled to hydraulic turbine (d) None of the above

What happens to the angle between current and voltage, when a small capacitance is added in series with a highly inductive circuit?  (A) Increases (B) Remains same as earlier angle (C) Decreases (D) Becomes indeterminant

A 3-phase, 50 Hz, 500 V induction motor develops 20 hp at slip of 5%. Mechanical losses are 1 hp, and stator loss is 1 kW. The efficiency will be   (a) 95.3% (b) 90.5% (c) 91.3% (d) 85.3%

The maximum possible power of a 3-phase synchronous motor with synchronous reactance 0.8 p.u. connected to a bus-bar of 1.0 p.u. and excitation adjusted to 1.2 p.u. is (A) 0.5 p.u. (B) 0.96 p.u. (C) 1.5 p.u. (D) 1.8 p.u.