Three lamps with 40 Ω, 30 Ω, and 15 Ω resistance are connected in parallel to a 90 volt circuit. What is the total current used by the three lamps?
A) 0.94 A

B) 15.25 A

C) 11.25 A

D) 1.06 A

Option C) 11.25 A

Explanation:

Given that:

Voltage V = 90 volts

total current I = ?

Three resistors each with 40 Ω, 30 Ω, and 15 Ω in parallel, the equivalent resistance of the combination (Rtotal) of the circuit is as follows:

i.e 1/Rtotal = (1/R1 + 1/R2 + 1/R3)

1/Rtotal = (1/40Ω + 1/30Ω + 1/15Ω)

1/Rtotal = (3 + 4 + 8)/120Ω

1/Rtotal = 15/120Ω

1/Rtotal = 1/8Ω

To get the value of Rtotal, cross multiply

Rtotal x 1 = 8Ω x 1

Rtotal = 8Ω

Then, apply the formula V = I x Rtotal

90 volts = I x 8Ω

I = 90 volts / 8Ω

I = 11.25 Amperes

Thus, the total current used by the three lamps is 11.25 Amperes

in this image, you can see solar radiation going through ocean water.

no image, but probably absorption

heat the gas and measure the pressure