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.
Bacteria doesn't produce energy they are dependent upon their substrate in case of lack of nutrients they are able to make spores which helps them to sustain in harsh environments
_Adnan
But not all bacteria make spores, l mean Eukaryotic cells have Mitochondria which acts as powerhouse for them, since bacteria don't have it, what is the substitution for it?
Assimilatory nitrate reduction is a process that occurs in some microorganisms, such as bacteria and archaea, in which nitrate (NO3-) is reduced to nitrite (NO2-), and then further reduced to ammonia (NH3).
Elkana
This process is called assimilatory nitrate reduction because the nitrogen that is produced is incorporated in the cells of microorganisms where it can be used in the synthesis of amino acids and other nitrogen products
There are nothing like emergency disease but there are some common medical emergency which can occur simultaneously like Bleeding,heart attack,Breathing difficulties,severe pain heart stock.Hope you will get my point .Have a nice day ❣️
_Adnan
define infection ,prevention and control
Innocent
I think infection prevention and control is the avoidance of all things we do that gives out break of infections and promotion of health practices that promote life