EMF and Internal Resistance (2)

[SJN]

Homework Statement

A battery consisting of six cells in series, each of e.m.f 1.5V and internal resistance 0.5 Ohms is connected to two 3 Ohm resistors which are in parallel. Calculate:
a) the total parallel resistance of the combination [1.67]
b) write down the internal resistance of the battery
c) calculate the current drawn from the batter [1.93]

Homework Equations

I = V/R

The Attempt at a Solution

I didn't know where to start :(


Thanks in advance,
Sam

 

[Jhero]

Hi Sam,

No problem, let's break this down step by step.

a) To find the total parallel resistance, we can use the formula 1/R(total) = 1/R1 + 1/R2, where R1 and R2 are the individual resistances of the two 3 Ohm resistors. Plugging in the values, we get 1/R(total) = 1/3 + 1/3 = 2/3. To get R(total), we take the reciprocal of both sides, giving us R(total) = 3/2 = 1.67 Ohms.

b) To find the internal resistance of the battery, we can use Ohm's law (V = IR) and rearrange it to solve for R. We know the voltage (1.5V) and the current (which we will find in part c), so we can plug those values in to find the internal resistance.

c) To calculate the current drawn from the battery, we can use Ohm's law again (I = V/R). The total resistance in the circuit is the sum of the parallel resistance (1.67 Ohms) and the internal resistance of the battery (which we will find in part b). Once we have the total resistance, we can plug that in along with the battery's voltage (1.5V) to find the current.

I hope this helps! Let me know if you have any further questions.