A loop circuit has a resistance of R1 and a current of 2.2 A. The current is reduced to 1.6 A when an additional 2.8 Ω resistor is added in series with R1. What is the value of R1? Assume the internal resistance of the source of emf is zero. Answer in units of Ω

Value of is 7.466 ohm

Explanation:

Let emf of the battery is e

In first case when only is there current through battery is 2.2 A

So

......eqn 1

In second case current is reduced to 1.6 A when additional resistance of 2.8 ohm is added in series

So

....eqn 2

Fro eqn 1 and eqn 2

So value of is 7.466 ohm

when heated, the valance electrons increased their speed and transferred the heat from electron to electron.   i just took the test.

one person pulls 90n one way and the other has 100n pulling the other way.

so the net force = 90 - 100 = -10n,

or the ans can be 10n if the picture shows -90n and 100n instead.