DC Motors Quiz

A DC motor where the field winding is connected in series with the armature winding, providing high starting torque but poor speed regulation.

A DC motor where the field winding is connected in parallel with the armature winding, offering relatively constant speed under varying loads.

A DC motor combining series and shunt windings, providing high starting torque and good speed regulation.

A DC motor that uses permanent magnets instead of field windings, simpler and more efficient but suitable for low power.

DC motors exhibit a linear relationship between torque and armature current; speed varies inversely with torque.

The percentage change in speed from no-load to full-load conditions; shunt and compound motors have better regulation than series motors.

The torque required to initiate rotation; series motors have the highest starting torque.

The ratio of mechanical output power to electrical input power; DC motors generally have high efficiency.

Adjusting a DC motor's speed by changing armature voltage (e.g., using variable resistors or PWM).

Controlling the force a motor produces by adjusting the armature current or field flux.

Using a DC motor as a generator to recover energy and brake the load.

Disconnecting a motor from the power and connecting it to a resistor to dissipate energy as heat.

Applications in factories using DC motors for tasks like conveyor belts and robots.

Using DC motors (like lathes, drills, mills) for precise machining.

Using DC motors in cars, buses, etc., as the main power source.

Connecting a motor directly to power without extra equipment; can cause high initial current.

Lowering the voltage to start a motor smoothly; less initial current.

Gradually increasing voltage for a smoother and safer start.

Controlling motor speed by changing the frequency of the power.

Stopping a motor by converting its kinetic energy into electrical energy.

Reversing current to quickly decelerate a DC motor.

Losses in a motor due to hysteresis and eddy currents in the iron core.

Motor losses caused by friction (bearings) and windage (air resistance).

Additional losses caused by interaction between armature and field magnetic fields.

Ratio of output power to input power, expressed as a percentage

Test to measure no-load conditions to determine core and stray losses.

Measures full-load current and armature resistance when the shaft is blocked.

Determines the motor's efficiency at various load conditions.

Electrical power supplied to the DC motor.

Using a variable resistor (rheostat) in the motor's circuit to dissipate energy and slow it down.

Reducing field current to lower back EMF, enabling higher speeds and braking.

Resistive loads used to dissipate energy during braking, supporting dynamic braking or plugging.

Reversing the motor's connections to rapidly stop it, useful in conveyor systems.

Adjusting the voltage to the motor's armature to control its speed, using a variable resistor.

Adjusting the magnetic field (flux) to control DC motor speed, by changing field current.

Varying the armature resistance to control speed, using electronic methods like PWM or choppers

Independently adjusting field current to control DC motor speed.

Electronically controlling DC motor speed by modulating the applied voltage/current.

Power loss due to resistance in the armature and field windings.

Precise control over the deceleration of a motor.

Reclaiming energy during braking, via methods like dynamic braking

Power wasted during operation, including copper losses and others.

A DC motor with field windings connected in series with the armature windings, resulting in high starting torque but variable speed.

A DC motor with field windings in parallel with the armature, providing relatively constant speed across varying loads.

A DC motor combining series and shunt windings, balancing high starting torque with good speed regulation.

A DC motor using permanent magnets for the magnetic field, offering simplicity and efficiency, but often used for low-power applications.

The relationship between torque and speed in a DC motor. Speed decreases as torque increases.

The change in speed from no-load to full-load, a crucial characteristic for stability in various applications.

The ability of a motor to rapidly accelerate under high load conditions, important for applications like lifting heavy objects.

The ratio of output power to input power. High efficiency means less energy is wasted.

Losses in a DC motor caused by hysteresis and eddy currents in the iron core.

Losses in a DC motor due to friction in bearings and windage (air resistance).

Additional losses in a DC motor from the interaction of armature and field magnetic fields.

Ratio of output power to input power, expressed as a percentage.

A test to measure no-load speed, current, and input power to determine core and stray losses.

Test to determine full-load current, armature resistance, and input power when the motor shaft is blocked.

Test to determine a DC motor's efficiency at various load conditions.

Electrical power supplied to the DC motor.

A braking method for DC motors that uses a variable resistor (rheostat) in the armature circuit to dissipate energy and slow the motor down.

Braking method in DC motors with field weakening capability, reduced field current lowers back EMF, allowing for faster speed and braking.

Resistive loads connected across motor terminals to dissipate energy during braking, often with dynamic braking or plugging.

Rapidly decelerating a motor by reversing the current flow.

Method to control DC motor speed by varying voltage applied to the armature.

Method for controlling DC motor speed by adjusting the magnetic field strength.

Method to control DC motor speed by changing armature resistance using electronic methods.

Method to control DC motor speed by independently adjusting field current.

Electronically modulating voltage/current to control DC motor speed, often including acceleration/braking.

Power loss due to resistance in the armature and field windings.

Precisely controlling the deceleration rate of a motor, regulating stopping distances.

Regenerative methods recover energy during braking, feeding energy back to the system.

Power wasted during DC motor operation, including copper, iron, and mechanical losses.

Adjusting the speed of a DC motor by changing the armature voltage using methods like armature resistance, field flux, or electronic methods like PWM.

Controlling the rotational force (torque) a DC motor produces by adjusting its armature current or field flux.

Converting a DC motor's kinetic energy back to electrical energy during braking by reversing the armature voltage.

Stopping a DC motor by disconnecting it from the power supply and connecting it to a resistor to dissipate the kinetic energy as heat.

Using DC motors in factories for tasks like conveyor belts and robotic arms.

Using DC motors in tools like lathes, milling machines, and drills for precise work.

Using DC motors in cars, buses, and bikes for traction (moving the vehicle).

Connecting a DC motor directly to the power supply without any extra equipment.

Starting a motor by initially reducing the voltage to limit the starting current.

Gradually increasing the voltage supplied to a motor to start smoothly, reducing the current surge.

Controlling the speed of a DC motor by varying the frequency and voltage of the power supply.

Stopping a motor by converting its kinetic energy back into electrical energy.

Stopping a motor quickly by reversing the motor's connections to create a braking torque.