Which of the following changes will increase the frequency of an oscillating pendulum?

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

If a man weight 155 lb on earth, specify

Natali [406]

For the answer to the question above, on Earth, a one-pound object has a mass of about 0.453592 kilograms.

Therefore the man's mass is 155 * 0.453592 = 70.30676 kilograms. 

The part about the Moon's gravity is irrelevant. While the weight of a person or object would be different on the Moon, the mass would be the same.

3 0

3 years ago

Will increasing length and cross-sectional area increase the resistance of an object?

Klio2033 [76]

Answer:

Increasing length increases resistance

increasing cross sectional area reduces the resistance

.

Explanation:

The formula for resistance of an object is

$r = d \frac{l}{a}$

where r is resistance, d is resistivity of the material, l is length of material and a is cross sectional area of the object. This equation shows us that resistance is directly proportional to length and inversely proportional to cross sectional area. Hence, increasing length increases resistance while increasing cross sectional area reduces the resistance.

If these 2 variables are varied to the same extent, the net effect can be zero on the resistance.

5 0

3 years ago

Using a scale of 1 cm to represent 10 N, find the size and direction of the resultant of forces of 50 N

marta [7]

Answer:

$74.31\ \text{N}$

$16.59^{\circ}$

Explanation:

P = 50 N

Q = 30 N

$\theta$ = Angle between the vectors = $45^{\circ}$

Resultant is given by

$R=\sqrt{P^2+Q^2+2PQ\cos\theta}\\\Rightarrow R=\sqrt{50^2+30^2+2\times 50\times 30\times \cos45^{\circ}}\\\Rightarrow R=74.31\ \text{N}$

Angle of resultant

$\phi=\tan^{-1}\dfrac{Q\sin\theta}{P+Q\cos\theta}\\\Rightarrow \phi=\tan^{-1}\dfrac{30\times \sin45^{\circ}}{50+30\cos45^{\circ}}\\\Rightarrow \phi=16.59^{\circ}$

Magnitude of the resultant is $74.31\ \text{N}$

Direction of the resultant is $16.59^{\circ}$

4 0

3 years ago

Which statement about a wave produced by a doorbell is true?

vfiekz [6]

"It propagates in the form of compression and rarefactions" is the one statement among the following choices given in the question that is true about a wave produced by a doorbell. The correct option among all the options that are given in the question is the second option or option "B". I hope the answer helps you.

3 0

3 years ago