Need help big time!!!!

How do you change the currents in a circuit

mel-nik [20]

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Eddy Current Testing

Introduction
Basic Principles
History of ET
Present State of ET

The Physics
Properties of Electricity
Current Flow & Ohm's Law
Induction & Inductance
Self Inductance
Mutual Inductance
Circuits & Phase
Impedance
Depth & Current Density
Phase Lag

Instrumentation
Eddy Current Instruments
Resonant Circuits
Bridges
Impedance Plane
Display - Analog Meter

Probes (Coils)
Probes - Mode of Operation
Probes - Configuration
Probes - Shielding
Coil Design
Impedance Matching

Procedures Issues
Reference Standards
Signal Filtering

Applications
Surface Breaking Cracks
SBC using Sliding Probes
Tube Inspection
Conductivity
Heat Treat Verification
Thickness of Thin Mat'ls
Thickness of Coatings

Advanced Techniques
Scanning
Multi-Frequency Tech.
Swept Frequency Tech.
Pulsed ET Tech.
Background Pulsed ET
Remote Field Tech.

Quizzes

Formulae& Tables
EC Standards & Methods
EC Material Properties
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Current Flow and Ohm's Law

Ohm's law is the most important, basic law of electricity. It defines the relationship between the three fundamental electrical quantities: current, voltage, and resistance. When a voltage is applied to a circuit containing only resistive elements (i.e. no coils), current flows according to Ohm's Law, which is shown below.

I = V / R

Where:

I =

Electrical Current (Amperes)

V =

Voltage (Voltage)

R =

Resistance (Ohms)

Ohm's law states that the electrical current (I) flowing in an circuit is proportional to the voltage (V) and inversely proportional to the resistance (R). Therefore, if the voltage is increased, the current will increase provided the resistance of the circuit does not change. Similarly, increasing the resistance of the circuit will lower the current flow if the voltage is not changed. The formula can be reorganized so that the relationship can easily be seen for all of the three variables.

The Java applet below allows the user to vary each of these three parameters in Ohm's Law and see the effect on the other two parameters. Values may be input into the dialog boxes, or the resistance and voltage may also be varied by moving the arrows in the applet. Current and voltage are shown as they would be displayed on an oscilloscope with the X-axis being time and the Y-axis being the amplitude of the current or voltage. Ohm's Law is valid for both direct current (DC) and alternating current (AC). Note that in AC circuits consisting of purely resistive elements, the current and voltage are always in phase with each other.

Exercise: Use the interactive applet below to investigate the relationship of the variables in Ohm's law. Vary the voltage in the circuit by clicking and dragging the head of the arrow, which is marked with the V. The resistance in the circuit can be increased by dragging the arrow head under the variable resister, which is marked R. Please note that the vertical scale of the oscilloscope screen automatically adjusts to reflect the value of the current.

See what happens to the voltage and current as the resistance in the circuit is increased. What happens if there is not enough resistance in a circuit? If the resistance is increased, what must happen in order to maintain the same level of current flow?

4 0

4 years ago

Leah is making a chart to compare and contrast renewable and non-renewable resources. Which of the following would best complete

Sedbober [7]

Answer:

d. Can be replaced at the same rate or faster than they are used

Explanation:

I just took the test, and its the right answer. Your welcome ✌

6 0

3 years ago

Read 2 more answers

In each case, lifting or pushing, why must you exert a force to move the object? Q1-2: How much more effort is required to lift

musickatia [10]

Answer:

Newton's first law applies. An object at rest will stay that way until a force is applied.
Any amount of effort can be applied to any amount of mass (in the ideal case). The question is not sufficiently specific.

Explanation:

A force is required to move an object because the object will stay at rest until a force is applied.

__

The effort required to lift or push two masses instead of one depends on the desired effect. For the same kinetic energy, no more effort is required. For the same momentum, half the effort is required for two masses. For the same velocity, double the effort is required.

4 0

3 years ago

For a science project, you would like to horizontally suspend an 8.5 by 11 inch sheet of black paper in a vertical beam of light

liubo4ka [24]

Answer:

I = 3.9 x 10⁷ W/m²

Explanation:

given,

Sheet of black paper dimension = 8.5 x 11 inch

Area of sheet = 8.5 x 11 = 93.5 inch^2

1 inch =0.0254 m

Area = 0.06032 m²

mass of sheet = 0.80 g

Force = m g = 0.8 x 9.8 x 10⁻³ N

= 7.84 x 10⁻³ N

speed of light = c = 3 x 10⁸ m/s

Using equation

$F = \dfrac{IA}{c}$

where I is the intensity of light

$7.84 \times 10^{-3} = \dfrac{I\times 0.06032}{3 \times 10^8}$

$2.352 \times 10^{6} = I\times 0.06032$

$I = \dfrac{2.352 \times 10^{6}}{0.06032}$

I = 3.9 x 10⁷ W/m²

Intensity of the light is equal to I = 3.9 x 10⁷ W/m²

4 0

3 years ago

When the car is moving the unbalanced force acting on the car is 150 N.

dsp73

Answer:

F = m a, a = 0.3 m / s²

this acceleration points in the direction of the unbalanced force

Explanation:

In this problem we must use Newton's second law. Let's fix a reference system with the x axis parallel to the surface and the y axis perpendicular

Y axis y

N-W = 0

N = W = mg

X axis

∑ F = m a

F = m a

we substitute

150 = m a

To find an acceleration value, the mass of the car must be known, if the mass is m = 500 kg

a = 150/500

a = 0.3 m / s²

this acceleration points in the direction of the unbalanced force

8 0

3 years ago