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What does a negative velocity mean?

To understand this question, it is important to know that velocity has both a direction and a magnitude. The magnitude can be expressed by the unit m/s, however the direction is expressed by a vector. To dis...
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Answered by Thomas D. • Physics tutor
34705 Views

The Alternating Current Flowing through the Primary Coil of the Transformer Creates an Alternating Current in the Secondary coil. Explain how!

The alternating current creates an alternating magnetic field across the transformer. A magnetic field develops in the iron core of the transformer. This causes a potential difference to be induced across th...
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Answered by Arthur G. • Physics tutor
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A simple circuit contains a battery rated at 12V, connected in series to a filament lamp with a resistance of 3 ohms. What current flows through the filament lamp?

V=IR, where V is voltage (volts), I is current (amps) and R is resistance (ohms). Since V and R are known, I needs to be found. Rearranging the equation gives: I=V/R. Inputting the values gives I=12/3. I=4A
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Answered by Tom V. • Physics tutor
5893 Views

Why does your hair stand on end when you touch a Van de Graaff generator?

This is all down to static electricity. Inside the Van de Graaff generator, there is a rubber band and rollers. As they are electrically insulated, when the motor turns they rub together and electrons are 'k...
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Answered by Tom W. • Physics tutor
83043 Views

What is the difference between a scalar and a vector?

As often described, a vector is a quantity that has a magnitude and a direction, whereas a scalar just has a magnitude. The easiest way to thing about it is to physically think if you could point in a direct...
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Answered by Pavit B. • Physics tutor
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