Students’ understanding of the inverse square law in electrostatics

One problem of learning Electrostatics is that students often learn from their commonsense beliefs about electric force and electric field. This study investigated students’ conceptual understanding of finding electric force, electric field, and electric potential of point charge after learning an introductory physics course. We administered the Electrostatics Conceptual Evaluation Test to four lecture-based classes in high school. The first question was a comparison of the electric force from two-point charges at two different positions and the second question was a comparison of the electric field from a point charge at two different positions. The use of the inverse square law is required to find the electric force and the electric field at various positions. It was found that many students answered incorrectly. They described that the electric force and the electric field decrease whereas the distance increases by neglecting the inverse square law. This finding can be particularly used to suggest high school teachers to develop their effective strategy to support student learning.

Dust dynamics during the plasma afterglow

The charge and dynamics of dust particles in an afterglow plasma are studied using a 1D model in the diffusion approximation, taking into account the transition from ambipolar to free diffusion. It is analyzed how external conditions (dust particle size, neutral gas pressure and initial electron density) affect the dust motion. The dust particle dynamics has been examined in microgravity conditions and in presence of gravity. Without gravity, the location of dust particles in plasma volume may change essentially during the afterglow if the dust size and pressure are small (≤ 10 nm and ≤ 30 mTorr, respectively). At small pressures, in the very beginning of afterglow, small nanoparticles move to the plasma boundary because the ion drag force dominates over the electric force. At afterglow times when the electron temperature becomes time-independent, the ion drag force decreases faster with time than the electric force due to the ion density decrease, and dust particles may move to the slab center. In presence of gravity, the effect of gravity force on dust particles is important only at large afterglow times (t ≥ 10 ms), when the electric and ion drag forces are small. The dust dynamics depends essentially on the initial plasma density. If the density is large (~ 1012 cm-3), small nanoparticles (≤ 10 nm) may deposit on plasma walls in the beginning of plasma afterglow because of an enhancement of the ion drag force.

Effect of application of electric force to diesel fuel droplets charged through Millikan oil-drop experiment on physical and thermal characteristics of flame

This paper proposes a new feasible method to allow continuous change in the primary injection spray cone angle of liquid fuel droplets, which are injected from nozzles in liquid fuel combustion systems, to control the flame shape and thermal characteristics of the flame. The method is based on electric force applied to fuel droplets charged through frictional effects between the internal surface of the nozzle and the fuel flow as the liquid fuel is sprayed (based on the Millikan oil-drop experiment). A sprint computational fluid dynamics (CFD) code was developed to investigate the effect of application of electric force to charged diesel fuel droplets, which were injected from a pressure swirl atomizer, on physical and thermal characteristics of a two-dimensional axisymmetric turbulent jet diffusion flame. The results show that an electric field applied to charged fuel droplets (electric force) changes the spatial distribution of the liquid fuel droplets in the flame reaction zone. An applied electric force in (−y) direction diverts the fuel droplets towards the axis centerline of the furnace and, consequently, decreases the primary injection cone angle and increases the concentration of the evaporated droplets around the axis centerline, which enhances the fuel-oxidant mixing rate and raises the flame temperature. Unlike an applied electric force in (−y) direction, an applied electric force in (+y) direction decreases the flame temperature. However, as the primary injection cone angle is decreased, an applied electric force in (+y) direction increases the flame temperature.

Experimental investigation of an unusual induction effect and its interpretation as a necessary consequence of Weber electrodynamics

The magnetic force acts exclusively perpendicular to the direction of motion of a test charge, whereas the electric force does not depend on the velocity of the charge. This article provides experimental evidence that, in addition to these two forces, there is a third electromagnetic force that (i) is proportional to the velocity of the test charge and (ii) acts parallel to the direction of motion rather than perpendicular. This force cannot be explained by the Maxwell equations and the Lorentz force, since it is mathematically incompatible with this framework. However, this force is compatible with Weber electrodynamics and Ampère's original force law, as this older form of electrodynamics not only predicts the existence of such a force but also makes it possible to accurately calculate the strength of this force.

Experimental investigation of an unusual induction effect and its interpretation as a necessary consequence of Weber electrodynamics

The magnetic force acts exclusively perpendicular to the direction of motion of a test charge, whereas the electric force does not depend on the velocity of the charge. This article provides experimental evidence that, in addition to these two forces, there is a third electromagnetic force that (i) is proportional to the velocity of the test charge and (ii) acts parallel to the direction of motion rather than perpendicular. This force cannot be explained by the Maxwell equations and the Lorentz force, since it is mathematically incompatible with this framework. However, this force is compatible with Weber electrodynamics and Ampère's original force law, as this older form of electrodynamics not only predicts the existence of such a force but also makes it possible to accurately calculate the strength of this force.

Identification of Power Quality Disturbance

The nature of electric force and unsettling influences happened in power signal has gotten a significant issue between the electric force providers & clients. For enhancing the force quality constant checking of force is required that is being conveyed at client's destinations. Thusly, recognition of “POWER QUALITY” aggravations, and appropriate characterization of “POWER QUALITY” D is profoundly attractive. The location and characterization of the “POWER QUALITY” D in appropriation frameworks are significant errands for insurance of force conveyed network. The majority of the unsettling influences are non-fixed and temporary in quality thus it needs progressed apparatuses and methods for the evaluation of “Power quality” unsettling influences. In this research a cross breed method is utilized for describing “POWER QUALITY” unsettling influences utilizing wavelet change and fluffy rationale. A no of “POWER QUALITY” is showed in this work before include extrication measure. Two unmistakable highlights basic to all “POWER QUALITY” unsettling influences as Energy and Total Harmonic Distortion (THD) are differently utilises discrete wavelet change and are taken care of as contributions to the fluffy master framework for exact location and order of different “POWER QUALITY” unsettling influences. The fluffy master framework characterizes the “POWER QUALITY” aggravations as well as shows whether the unsettling influence is unadulterated or accommodates music. A neural organization follow PQ Disturbance (“POWER QUALITY” D) location framework is included displayed executing many layer feed forward Neural Network ‘MFNN’.