# Thread: ohms and power law

1. ## ohms and power law

find the resistance of an electric light bulb if there is a current of 0.8 A and a voltage potential difference of 120 V.

thankyou for any help with this one.

2. Originally Posted by rcmango
find the resistance of an electric light bulb if there is a current of 0.8 A and a voltage potential difference of 120 V.

thankyou for any help with this one.
we use ohm's law here, the equation is

V = IR

where V is the voltage, I is the current in amps and R is the resistance in ohms

=> R = V/I = 120/0.8 = 150 ohms

3. Originally Posted by Jhevon
we use ohm's law here, the equation is

V = IR

where V is the voltage, I is the current in amps and R is the resistance in ohms

=> R = V/I = 120/0.8 = 150 ohms
Again, since the unit is named for a person it needs to be capitalized, so the unit is "Ohms."

-Dan

4. Originally Posted by topsquark
Again, since the unit is named for a person it needs to be capitalized, so the unit is "Ohms."

-Dan
My apologies again

5. Thanks for the help on this one. Also, i'll be sure to use "Ohms in the future, also"

6. Originally Posted by topsquark
Again, since the unit is named for a person it needs to be capitalized, so the unit is "Ohms."

-Dan
I know this is a little old, but this is incorrect.

You may refer to section 5.2 of the SI brochure (http://www.bipm.org/utils/common/pdf...chure_8_en.pdf), which specifies that names of all units are treated as ordinary nouns and start with a lower-case letter even when the symbol for the unit begins with a capital letter. Section 5.1 states that the first letter of a symbol is capitalized only if it is derived from a proper name (for instance Hz for hertz), or to avoid confusion (for instance, litre is allowed to be represented by L since the lower-case el looks the numeral one).