contestada

PLLLLLLZ HELP 15 POINTS

A 10-ω resistor and a 30-ω resistor are connected in series across a 100-V battery. In another combination, a 10-ω resistor and a 30-ω resistor are connected in parallel across a 100-V battery. The ratio of the potential difference across the 10-ω resistor in the series combination to that of the 10-ω resistance connected in parallel is:


1/4

1/2

1/3

1/5

Respuesta :

Option A is the correct answer.

Explanation:

A 10-ω resistor and a 30-ω resistor are connected in series across a 100-V battery

Total resistance = 10 + 30 = 40 ω

We have

            Voltage = Current x resistance

            100 = I x 40

              I = 2.5 A

In series current in all the resistors are same, that is 2.5 A

             Voltage in 10ω resistor, V = I x 10 = 2.5 x 10 = 25 V

In parallel connection potential in all the resistors are same.

             Voltage in 10ω resistor, V = 100 V

The ratio of the potential difference across the 10-ω resistor in the series combination to that of the 10-ω resistance connected in parallel = 25/100 = 1/4

Option A is the correct answer.