- #1

predentalgirl1

- 67

- 1

**Show the quantity volts squared per ohm (V^2/ohm) has SI units of power.**

**P = V x I**

where

P is the power (watt or W)

V is the potential difference (volt or V)

I is the current (ampere or A)

From Ohm’s law

I = V / R

where

R is the resistance (Ohm or Ω).

So substituting in the above equation

P = V x (V/R)

P = V2 /R

So in unit , watt = (volt)2 / Ω

OR

I can rewrite, V^2/R = V.V/R = V.I

From definition of potential difference as Work done per unit charge, V = W/q

Unit volt, V = unit of W/unitof chaarge = J/C

Also current = charge/time

I = C/s

so, V^2/R = V.V/R = V.I

= J/C xC/s = J/s

= watt, (unit of power.)

Which seems most reasonable?

where

P is the power (watt or W)

V is the potential difference (volt or V)

I is the current (ampere or A)

From Ohm’s law

I = V / R

where

R is the resistance (Ohm or Ω).

So substituting in the above equation

P = V x (V/R)

P = V2 /R

So in unit , watt = (volt)2 / Ω

OR

I can rewrite, V^2/R = V.V/R = V.I

From definition of potential difference as Work done per unit charge, V = W/q

Unit volt, V = unit of W/unitof chaarge = J/C

Also current = charge/time

I = C/s

so, V^2/R = V.V/R = V.I

= J/C xC/s = J/s

= watt, (unit of power.)

Which seems most reasonable?