How much power is produced if a voltage of #7 V# is applied to a circuit with a resistance of #42 Omega#?

2 Answers
Jun 29, 2018

The power is #=1.17W#

Explanation:

The power is

#P=UI#

and Ohm's Law is

#U=RI#

#I=U/R#

Therefore,

#P=U*U/R=U^2/r#

The voltage is #U=7V#

The resistance is #R=42 Omega#

Therefore,

The power is

#P=(7^2)/42=49/42=1.17W#

Jun 29, 2018

Approximately #1.17# watts.

Explanation:

Power in here is given by the equation:

#P=V^2/R#

where:

  • #P# is the power in watts

  • #V# is the voltage in volts

  • #R# is the resistance in ohms

So, we get:

#R=(7 \ "V")^2/(42 \ Omega)#

#=(49 \ "V"^2)/(42 \ Omega)#

#~~1.17 \ "W"#