In an experiment this circuit is set up. Three ammeters are used to record the currents in the three vertical branches (with
R1 ,
R2 , and
E) . The readings of the ammeters in the resistor branches (i.e. currents in
R1 and
R2 ) are 2 A and 3 A respectively.
Find the equation obtained by applying Kirchhoff’s loop rule in the loop involving
R1 and
R2 .
What will be the reading of the third ammeter (i.e. the branch with
E )? If
E were replaced by 3
E , how would this reading change?
If the original circuit is modified by adding another voltage source (as shown in the following circuit), find the readings of the three ammeters.
In this circuit, assume the currents through
R1 ,
R2 and
R3 are
I1 ,
I2 and
I3 respectively and all are flowing in the clockwise direction.
Find the equation obtained by applying Kirchhoff’s junction rule at point A.
Find the equations obtained by applying Kirchhoff’s loop rule in the upper and lower loops.
Assume
R1 =
R2 = 6 Ω,
R3 = 12 Ω,
r1 =
r2 = 0 Ω,
E1 = 6 V and
E2 = 4 V. Calculate
I1 ,
I2 and
I3 .
For the situation in which
E2 is replaced by a closed switch, repeat parts (a) and (b). Using the values for
R1 ,
R2 ,
R3 ,
r1 and
E1 from part (c) calculate the currents through the three resistors.
For the circuit in part (d) calculate the output power of the voltage source and across all the resistors. Examine if energy is conserved in the circuit.
A student implemented the circuit of part (d) in the lab and measured the current though one of the resistors as 0.19 A. According to the results calculated in part (d) identify the resistor(s). Justify any difference in measured and calculated value.
I
1 + I
3 = I
2
E
1 - I
1 R
1 - I
2 R
2 - I
1 r
1 = 0;
-E
2 + I
1 R
1 - I
3 R
3 - I
3 r
2 = 0
I
1 = 8/15 A,
I
2 = 7/15 A and
I
3 =
- 1/15 A
I
1 = 2/5 A,
I
2 = 3/5 A and
I
3 = 1/5 A
P
E1 = 18/5 W and
P
R1 = 24/25 W,
P
R2 = 54/25 W,
P
R3 = 12/25 W. Yes,
P
E1 =
P
R1 +
P
R2 +
P
R3
Kirchhoff’s rules can be used to analyze any circuit, simple or complex.
Kirchhoff’s first rule—the junction rule: The sum of all currents entering a junction must equal the sum of all currents leaving the junction.
Kirchhoff’s second rule—the loop rule: The algebraic sum of changes in potential around any closed circuit path (loop) must be zero.
The two rules are based, respectively, on the laws of conservation of charge and energy.
When calculating potential and current using Kirchhoff’s rules, a set of conventions must be followed for determining the correct signs of various terms.
The simpler series and parallel rules are special cases of Kirchhoff’s rules.
Conceptual questions
Can all of the currents going into the junction in
[link] be positive? Explain.
Apply the junction rule to junction b in
[link] . Is any new information gained by applying the junction rule at e? (In the figure, each emf is represented by script E.)
(a) What is the potential difference going from point a to point b in
[link] ? (b) What is the potential difference going from c to b? (c) From e to g? (d) From e to d?
Consider the circuit in
[link] , and suppose that the emfs are unknown and the currents are given to be
,
, and
. (a) Could you find the emfs? (b) What is wrong with the assumptions?
(a) No, you would get inconsistent equations to solve.
(b)
. The assumed currents violate the junction rule.
The lymphatic system plays several crucial roles in the human body, functioning as a key component of the immune system and contributing to the maintenance of fluid balance. Its main functions include:
1. Immune Response: The lymphatic system produces and transports lymphocytes, which are a type of
asegid
to transport fluids fats proteins and lymphocytes to the blood stream as lymph
Anatomy is the study of the structure of the body, while physiology is the study of the function of the body. Anatomy looks at the body's organs and systems, while physiology looks at how those organs and systems work together to keep the body functioning.
Enzymes are proteins that help speed up chemical reactions in our bodies. Enzymes are essential for digestion, liver function and much more. Too much or too little of a certain enzyme can cause health problems
Kamara
yes
Prince
how does the stomach protect itself from the damaging effects of HCl
the normal temperature is 37°c or 98.6 °Fahrenheit is important for maintaining the homeostasis in the body
the body regular this temperature through the process called thermoregulation which involves brain skin muscle and other organ working together to maintain stable internal temperature