Question

A blow-dryer and a vacuum cleaner each operate with a voltage of 120 V. The current rating of the blow-dryer is 14 A, while that of the vacuum cleaner is 4.2 A. Determine the power consumed by (a) the blow-dryer and (b) the vacuum cleaner. (c) Determine the ratio of the energy used by the blow-dryer in 16 minutes to the energy used by the vacuum cleaner in 43 minutes.

Answer 1

The correct solution is:

(a) 1680 W

(b) 504 W

(c) 1.240

Step-by-step explanation:

The given values are:

Voltage,

V = 120 V

Current of blow dryer,

I₁ = 14 A

Current of vacuum cleaner,

I₂ = 4.2 A

Time,

t₁ = 16 min

t₂ = 43 min

As we know,

⇒
`Power (P) = VI`

(a)

For blow dryer:

⇒
`P_1=V* I_1`

`=120* 14`

`=1680 \ W`

(b)

For Vacuum cleaner:

⇒
`P_2=V* I_2`

`=120* 4.2`

`=504 \ W`

(c)

The ratio will be:

=
`(Blow \ dryer \ energy)/(Vacuum \ cleaner \ energy)`

=
`(P_1* t_1)/(P_1* t_2)`

=
`(1680* 16)/(504* 43)`

=
`(26880)/(21672)`

=
`1.240`