DC Circuits Introductory Activity

Voltage­
● an electromotive force or potential difference expressed in volts. Voltage is measured in volts and is represented by the symbol V.

http://physics.tutorvista.com/electricity­and­magnetism/ohm­s­law.html

Resistance­
● Resistance is an electrical quantity that measures how the device or material reduces the electric current flow through it. Measured in ohms
(Ω) and represented by R.

https://www.google.com/search?q=resistance&espv=2&biw=1366&bih=667&source=lnms&tb m=isch&sa=X&ei=uRP3VJroO4mvyQSGvYHoBQ&ved=0CAYQ_AUoAQ#tbm=isch&q=resista nce+in+circuit&imgdii=_&imgrc=y9SFhM_QxcpFSM%253A%3BU8lmR34zQfgLRM%3Bhttp%
253A%252F%252Fmedia.cheggcdn.com%252Fmedia%252F9c5%252F9c56ab84­e01f­4850­
a9bf­83c2f2efdfba%252FphpSPtH0y.png%3Bhttp%253A%252F%252Fwww.chegg.com%252
Fhomework­help%252Fquestions­and­answers%252F­total­circuit­resistance­effective­req­q2
752274%3B713%3B391

Ohm’s Law­
● The electricity is the flow of charges from positive to negative or vice­versa. It is also said the flow of electrons. The one of important law of electricity is
Ohm's law
. This is also called a fundamental law of electricity. It gives the relationship between basic electrical quantities. These basic quantities are current, resistance, and voltage.

http://www.google.com/imgres?imgurl=http://upload.wikimedia.org/wikipedia/commons/7/78/Ohm%27s_Law
_Pie_chart.svg&imgrefurl=http://commons.wikimedia.org/wiki/File:Ohm%27s_Law_Pie_chart.svg&h=225&w
=225&tbnid=Vf9rUBo­7EXJ1M:&zoom=1&tbnh=160&tbnw=160&usg=__wQh_ntVLb4vz01sFWjfPb8Ra6iU=
&docid=VWhC0M4TuoRiLM&itg=1

Resistor­
● A resistor is a passive two­terminal electrical component that implements electrical resistance as a circuit element. Resistors act to reduce current flow, and, at the same time, act to lower voltage levels within circuits.

http://www.google.com/imgres?imgurl=https://dlnmh9ip6v2uc.cloudfront.net/assets/c/4/a/9/d/515c7a2bce395 f653d000002.png&imgrefurl=https://learn.sparkfun.com/tutorials/resistors&h=197&w=255&tbnid=nz0CYYXh nn2HwM:&zoom=1&tbnh=142&tbnw=183&usg=__bMr50vObN9z2woxBKUzyYtfQ1Ps=&docid=gA5Z9_AHZ gJO_M&itg=1 Ammeter­
● An ammeter is a measuring instrument used to measure the electric current in a circuit. Electric currents are measured in amperes (A)

https://encrypted­tbn1.gstatic.com/images?q=tbn:ANd9GcQkkEKpYYSL5zdxi9IBmGND
Jd2WrRhnMQnt4DUP53S5vrlzpkMq0AG1Ve­d

Voltmeter­
● A voltmeter is an instrument used for measuring electrical potential difference between two points in an electric circuit. Analog voltmeters move a pointer across a scale in proportion to the voltage of the circuit; digital voltmeters give a numerical display of voltage by use of a nalog to digital converter
.

https://www.google.com/search?q=voltmeter&biw=1366&bih=667&source=lnms&tbm=isch&sa=X&ei=QBX3
VPLGNs­ZyASKqoGQCQ&ved=0CAgQ_AUoAg#imgdii=_&imgrc=w9Zam4gfGToJaM%253A%3BPO3RPXf­
8_Bo3M%3Bhttp%253A%252F%252Fwww.futurlec.com%252FPictures%252FVolt_0­30V.jpg%3Bhttp%253
A%252F%252Fwww.futurlec.com%252FPanel_Meters.shtml%3B250%3B226

Amp­
● Short for ampere. the practical meter­kilogram­second unit of electric current that is equivalent to a flow of one coulomb per second or to the steady current produced by one volt applied across a resistance of one ohm

https://encrypted­tbn2.gstatic.com/images?q=tbn:ANd9GcQAIKx4jc01TkyyZYYyvLGdbwxZuV
Xk6NsYDAUCft_dT0ogmY6XUNuJlhU

Ohm­
● The SI unit of electrical resistance, expressing the resistance in a circuit transmitting a current of one ampere when subjected to a potential difference of one volt.

https://encrypted­tbn1.gstatic.com/images?q=tbn:ANd9GcQDorOGguqLzL00AMHoADSYexv
3L_WG­pmdGCYzoS9­XP53VHnUHCBXn4B7

Voltage over battery

Voltage over bulb

Current before the bulb Current after the bulb 1.5V

1.5V

0.15 Amps

0.15 Amps

3V

3V

0.30 Amps

0.30 Amps

9V

9V

0.90 Amps

0.90 Amps

12V

12V

1.20 Amps

1.20 Amps

4.Voltage and current are directly related.
5. The current before and after the light bulb are the same.
6. If you double the voltage, current would also double.

7.The current from a .75V battery would be .075 amps.