Ev Training Quiz – Hero Electric & Isieindia Industry Project

A modern wind turbine typically has three blades. This design is commonly used because it strikes a balance between efficiency and stability. Having three blades allows the turbine to capture a significant amount of wind energy while still maintaining stability in varying wind conditions. Additionally, three blades are generally easier to manufacture and maintain compared to turbines with a larger number of blades.

A space truss is a structure made of slender members that are joined together at their end points. The term "space" refers to the three-dimensional nature of the truss, as it can extend in multiple directions. Trusses are commonly used in engineering and architecture to provide stability and support for various structures such as bridges and roofs. By distributing the load along the members, a space truss can efficiently transfer forces and maintain structural integrity.

Angular displacement, angular velocity, and angular acceleration are all vector quantities because they have both magnitude and direction. Angular displacement refers to the change in the position or orientation of an object, angular velocity refers to the rate at which the object rotates, and angular acceleration refers to the rate at which the angular velocity changes. Since all three quantities have both magnitude and direction, they can be represented as vectors.

The emf of a dry cell refers to its electromotive force, which is the maximum potential difference it can provide to a circuit. A dry cell typically has an emf of 1.5 V, which means it can provide a maximum potential difference of 1.5 volts to a circuit. This is a common value for many standard dry cell batteries used in various electronic devices.

Coplaner concurrent forces are forces that meet at one point and their lines of action also lie on the same plane. This means that the forces are not only acting at the same point, but they are also acting in the same plane. This is in contrast to coplaner non-concurrent forces, which may also lie on the same plane but do not meet at one point. Non-coplaner concurrent forces refer to forces that meet at one point but their lines of action do not lie on the same plane. Non-coplaner non-concurrent forces are forces that neither meet at one point nor lie on the same plane.

A damper winding is used in synchronous machines to maintain mechanical stability. It consists of short-circuited conductors placed in slots on the rotor. When the rotor experiences mechanical disturbances, such as sudden changes in load or faults, the damper winding helps to dampen the oscillations and stabilize the machine. This is achieved by inducing eddy currents in the conductors, which create a magnetic field that opposes the mechanical disturbances. By doing so, the damper winding helps to prevent excessive vibrations and maintain the mechanical integrity of the synchronous machine.

Deflection refers to the vertical distance between the axis of a beam before and after loading at a specific point. It is a measure of how much the beam bends or flexes under the applied load. Deformation, on the other hand, is a more general term that refers to any change in shape or size of an object. Slope is not the correct term in this context, as it typically refers to the inclination or steepness of a line or surface. Therefore, the correct answer is deflection.

A compressor is not a part of a modern wind turbine. Wind turbines convert the kinetic energy of wind into electrical energy through the use of a rotor, which consists of blades connected to a hub. The blades capture the wind's energy and transfer it to the rotor, which is connected to a generator. The generator then converts the mechanical energy into electrical energy. The other options mentioned (gear box, nacelle, and yaw drive) are all components that are typically found in a modern wind turbine.

According to the principle of conservation of energy, the sum of potential energy (P.E) and kinetic energy (K.E) of a particle remains constant under the action of a conservative force. A conservative force is a type of force that does not dissipate or remove energy from the system. It can be stored as potential energy and converted into kinetic energy without any loss. Examples of conservative forces include gravitational force and elastic force.

The center of gravity of a quadrant of a circle lies along its central radius at a distance of 0.6r. This is because the center of gravity of any symmetrical shape lies along its axis of symmetry, which in this case is the central radius. The distance from the center of gravity to the center of the circle is determined by dividing the length of the central radius by the ratio of the area of the quadrant to the area of the entire circle, which is 1/4. Therefore, the distance is 0.6 times the length of the central radius.

The power generated by an engine can be calculated using the formula: Power = Work done / Time taken. In this case, the work done by the engine is given as 1000 joules and the time taken is 6 seconds. Therefore, the power generated by the engine is 1000 joules / 6 seconds = 166 watts.

When analyzing a truss, both compressive force and tensile force are determined. Compressive force refers to the force that pushes or compresses the structural members of the truss, while tensile force refers to the force that pulls or stretches the members. Both types of forces need to be considered in order to accurately analyze the axial forces acting on the truss.

In the design of space trusses, the loads are applied at the joints. This means that the forces and external loads are concentrated at the connection points between the truss members. By applying the loads at the joints, the truss structure can efficiently distribute and transfer the forces throughout the entire system. This design approach ensures that the truss can effectively withstand and support the applied loads without excessive stress concentrations or structural failures.

A machine having an efficiency greater than 50% is known as a reversible machine. This means that the machine is able to convert a higher percentage of the input energy into useful work output. In a reversible machine, there is minimal energy loss or waste, making it highly efficient.

When the assumption of the direction of the force in space trusses is made, and it turns out to be in the opposite sense, it means that the actual direction of the force is opposite to what was assumed. Therefore, the direction of the force is known to us because it is the opposite of the assumed direction. This suggests that the assumption made was incorrect and the question cannot be solved further based on that assumption.

When bridges are extended over long routes or distances, a rocker or a roller is used at the joints. This is because when a bridge expands or contracts due to temperature changes or other factors, the joints need to be able to move freely to prevent structural damage. A rocker or a roller allows for this movement by providing a flexible connection between the bridge segments.

The correct answer is solar cell because satellites rely on solar panels to convert sunlight into electricity. These solar cells are made up of photovoltaic materials that absorb photons from the sun and generate an electric current. This energy is then used to power the various systems and instruments on the satellite, including communication devices, sensors, and scientific instruments. Solar cells are preferred as a source of energy for satellites because they provide a sustainable and renewable source of power in space.

Electromagnetic torque is generated in rotating machines when both the stator and rotor windings carry current. This is because the interaction between the magnetic fields produced by the currents in the stator and rotor windings creates a force that causes the rotor to rotate. If only one of the windings carries current, there will be an imbalance in the magnetic fields, resulting in a reduced or no torque production. Therefore, for electromagnetic torque to be present, it is necessary for both the stator and rotor windings to carry current.

Trusses are structural elements that consist of straight members connected at joints. They are typically used to support roofs, bridges, and other structures. In this context, trusses are three-dimensional because they exist in a 3D volume. This means that they have length, width, and height, and can span across multiple planes. Therefore, the correct answer is 3D.

A utility scale wind turbine is a complex piece of machinery that requires numerous components to function properly. With the scale and complexity of these turbines, it is reasonable to assume that it takes more than just a few components to build one. The answer "More than 8,000" suggests that the number of components required is significantly high, indicating the intricate nature of utility scale wind turbines.

Most utility-scale wind turbine towers in the U.S. are approximately 86 meters (282 feet) tall.

The estimated energy available in the winds over the earth surface is 1.6 X 107 MW. This means that there is a significant amount of energy that can be harnessed from wind power. Wind turbines can convert the kinetic energy of the wind into electrical energy, and with this estimated amount of available energy, wind power has the potential to be a major source of renewable energy.

The Ward-Leonard system of speed control is not recommended for constant speed operation because it is primarily designed for applications that require variable speed control. The system uses a motor-generator set to control the speed of the motor by varying the voltage and frequency. This allows for precise control over the motor's speed, making it ideal for applications where speed needs to be adjusted frequently. However, for constant speed operation, other simpler and more efficient control systems can be used instead.

The Beaufort number is used to describe wind intensity based on observations of its effects on land or sea. It is a scale ranging from 0 to 12, with each number corresponding to a specific range of wind speeds and their associated effects. This scale was developed by Sir Francis Beaufort in the early 19th century and is still widely used today. The Beaufort number provides a simple and practical way to communicate wind intensity, making it a useful tool for various applications such as weather forecasting, maritime navigation, and aviation.

The range of control of the controller decreases due to the presence of offset. Offset refers to the difference between the desired setpoint and the actual process variable. When there is an offset, the controller needs to make adjustments to bring the process variable back to the setpoint. However, if the offset is present, it indicates that the controller is not able to fully control the process within the desired range. Therefore, the range of control decreases.

When the field resistance is increased in a speed control system, it leads to a decrease in the flux. This decrease in flux causes a decrease in the electromotive force (EMF) generated in the system. As a result, the speed of the system decreases. Therefore, the option "Increase in EMF" is incorrect as it contradicts the cause and effect relationship described above.

The correct answer is i,ii. Synchronizing power refers to the stiffness coefficient of electromagnetic coupling between the stator and rotor in a synchronous machine. It is also a stability measure of the machine, indicating how well it can maintain synchronization with the grid. The power consumption factor, on the other hand, is not related to synchronizing power.

The coupling angle or load angle of a synchronous motor is defined as the space angle between the rotor and stator poles of opposite polarity. This angle represents the phase difference between the rotor and stator magnetic fields, which is crucial for the motor's operation. By having opposite polarities, the rotor and stator poles attract each other, creating the necessary torque for the motor to rotate. Therefore, the coupling angle is determined by the positions of these opposite poles, indicating the alignment and interaction between the rotor and stator fields.

When the value of disturbance increases, the controller adjusts the set point by shifting it to a new value. This adjustment is known as offset. It allows the controller to maintain stability and compensate for the increased disturbance. The term "set-shift" is not commonly used in this context, and "stabilization" refers to the overall goal of maintaining stability rather than the specific action of adjusting the set point. Therefore, the correct answer is offset.

If the power angle δ exceeds the internal angle θ, the operation of a synchronous motor operating on constant excitation across an infinite bus will not be stable. This means that the motor will not be able to maintain a steady and synchronized rotation with the power system. The power angle represents the phase difference between the rotor and stator magnetic fields, while the internal angle θ represents the angle between the rotor flux and the resultant air-gap flux. If the power angle exceeds the internal angle, it indicates a loss of synchronization and instability in the motor's operation.

Heating and cooling of the atmosphere generate convection currents. When the air near the Earth's surface is heated, it becomes less dense and rises, creating an upward flow of air. As the heated air rises, it cools down and becomes denser, eventually sinking back down to the surface. This continuous cycle of warm air rising and cool air sinking creates convection currents, which play a significant role in the movement of air and the distribution of heat throughout the atmosphere.

To limit the armature current to 125% of its rated value, a high external resistance needs to be added in the armature circuit. The resistance value should be higher than the armature circuit's internal resistance in order to effectively limit the current. Among the given options, 31.1 Ω is the highest resistance value, making it the correct answer.

The PWM control of a DC motor varies linearly with speed because PWM (Pulse Width Modulation) is a technique that adjusts the average voltage applied to the motor by rapidly switching the power on and off. By varying the width of the pulses, the average voltage can be adjusted, which in turn controls the speed of the motor. As the width of the pulses increases, the average voltage and speed of the motor also increase in a linear relationship.

The velocity ratio of a machine is not the ratio of load lifted to the effort applied. The velocity ratio of a machine is the ratio of the distance moved by the effort to the distance moved by the load.

The output of a solar cell is typically around 1 W. Solar cells convert sunlight into electricity through the photovoltaic effect. The efficiency of solar cells varies, but on average, they can produce around 1 watt of power per square meter of solar panel. This output can be affected by factors such as the angle and intensity of sunlight, temperature, and the quality of the solar cell itself.

Armature voltage control provides the best speed control for small DC motors. By adjusting the voltage applied to the armature, the speed of the motor can be controlled effectively. This method allows for precise control over the motor's speed, making it ideal for applications where speed regulation is critical. Field resistance control, on the other hand, is not as effective in providing precise speed control. Therefore, the correct answer is armature voltage control.

When the shaft load of a 3-phase synchronous motor is reduced by half while keeping the field current constant, the motor will operate at a leading power factor. This means that the current will lead the voltage in the circuit. This change in power factor occurs because the motor is now operating at a higher excitation level than before, causing the current to lead the voltage. The power factor of a synchronous motor is dependent on its excitation level, and reducing the shaft load while keeping the field current constant increases the excitation level, resulting in a leading power factor.

An over excited machine refers to an alternator where the field current is increased beyond the normal value, resulting in a stronger magnetic field. This increased magnetic field makes the machine more stiff, meaning it has a higher resistance to changes in its operating conditions. On the other hand, the stability of an alternator is influenced by the air-gap length. A machine with a longer air-gap is less stable compared to one with a smaller air-gap. Therefore, statement (i) is true because an over excited machine is indeed more stiff, while statement (ii) is false because a machine with a longer air-gap is less stable.

The correct answer is direct load loss and stray load losses. Short circuit load losses refer to the losses that occur in a transformer when it is subjected to a short circuit condition. Direct load loss refers to the power loss that occurs in the resistance of the transformer windings when current flows through them. Stray load losses, on the other hand, refer to the losses that occur due to the leakage flux and eddy currents in the transformer's core and windings. Both direct load loss and stray load losses contribute to the overall short circuit load losses in a transformer.

The initial velocity of the object is given as 2 m/s. The force applied on the object is 40 N. Using Newton's second law of motion, force = mass x acceleration, we can calculate the acceleration of the object. Rearranging the formula, acceleration = force / mass. Plugging in the values, we get acceleration = 40 N / 30 kg = 4/3 m/s^2. To find the final velocity after 4 seconds, we can use the equation v = u + at, where v is the final velocity, u is the initial velocity, a is the acceleration, and t is the time. Plugging in the values, we get v = 2 m/s + (4/3 m/s^2) x 4 s = 2 m/s + 16/3 m/s = 22/3 m/s = 7.33 m/s. Therefore, the correct answer is 7.33 m/s.

Secondary cells are rechargeable batteries that can be used multiple times. They can be discharged and recharged repeatedly without any significant loss of capacity. Lead acid cells and alkaline cells are both examples of secondary cells. Lead acid cells are commonly used in automotive applications, while alkaline cells are commonly used in portable electronic devices. Therefore, the correct answer is both (a) and (b).

The correct answer is 100 ohm, 10 watts because the power (in watts) can be calculated using the formula P = I^2 * R, where P is power, I is current, and R is resistance. In this case, the current is 0.3 amperes and the resistance is 100 ohms. Plugging these values into the formula, we get P = (0.3)^2 * 100 = 0.09 * 100 = 9 watts. Since the power required is 9 watts, the resistor with a power rating of 10 watts is the most suitable choice.

A large stiffness coefficient represents that the motor speed remains practically constant. This means that the motor is able to maintain a consistent speed regardless of any fluctuations or changes in mechanical load. The stiffness coefficient is a measure of the motor's ability to resist changes in speed, and a large value indicates a high level of stability and consistency in the motor's performance.

The back emf peak set up in the stator of a synchronous motor depends on the rotor excitation. The rotor excitation refers to the magnetic field produced by the rotor. As the rotor excitation increases, the strength of the magnetic field also increases, leading to a higher back emf peak in the stator. Therefore, the level of rotor excitation directly affects the back emf peak in a synchronous motor. The other factors mentioned in the options, such as supply voltage, rotor speed, and load on the motor, may have an impact on the motor's performance but do not directly determine the back emf peak.

Lithium cells are able to operate within a temperature range of -50°C to 75°C. This means that they can function in both extremely cold and hot conditions. Operating outside of this temperature range may cause the lithium cells to malfunction or lose their effectiveness.

India holds 20,000 MW of wind power. This means that India has the capacity to generate 20,000 megawatts of electricity from wind energy sources. Wind power is a renewable energy source that is harnessed by using wind turbines to convert the kinetic energy of the wind into electrical energy. India's wind power capacity is significant and contributes to the country's efforts to increase its share of renewable energy in its overall energy mix.

In a roof supporting space truss, the load is transmitted first to the truss and then to the joints through purlins. This means that the load is initially supported by the truss members, which are designed to carry the load. The load is then transferred to the joints, which connect the truss members, and finally to the purlins, which distribute the load to the supporting structure of the roof. This sequence ensures that the load is efficiently transmitted from the roof to the supporting elements.

The statement suggests that the calculations involved in bridges are all 2D calculations because the loading in a bridge is different from simple trusses. However, this is not true. Bridge calculations involve both 2D and 3D calculations, as bridges are complex structures that require consideration of various factors such as the distribution of loads, material properties, and structural behavior in multiple dimensions.

The correct answer is "One H? and one E plane tee." A Magic Tee is a type of microwave component that combines two signals. It consists of one H-plane tee and one E-plane tee. The H-plane tee divides the signal into two equal parts, while the E-plane tee combines the signals in a specific way to achieve the desired output. Therefore, the combination of one H-plane tee and one E-plane tee is necessary to form a Magic Tee.

Moment of inertia is a property of a rotating object that determines its resistance to changes in its rotational motion, while conductance is a measure of how easily an electrical current can flow through a material. These two quantities are not analogous because they describe different aspects of different systems - rotational motion and electrical conductivity.