I will give 50 points so give right answer or I will report so pls no spam..
Q) A cell of emf 2v and interanal resistance 1.2 ohm and is connected to an ammeter of resistance 0.8 ohm and two resistors of 4.5 ohm and 9 ohm as shown in figure below
Find :-
a. the reading of the ammeter,
b.the potential difference accross the terminals of the cell , and
c.the potential difference accross the 4.5 ohm resistor m
Answers
Given :-
- Emf of cell, E = 2 V
- internal resistance of cell, R₁ = 1.2 Ω
- Resistance of ammeter, R₂ = 0.8 Ω
- Two resistors are connected as in figure, of resistances 4.5 Ω and 9 Ω
To find :-
- reading of ammeter means current in the circuit, I = ?
- potential difference across the terminals of the cell
- Potential difference across the 4.5 Ω Resistor.
Knowledge required :-
- Relation b/w Resistance (R), Emf (E) , and current (I) in a circuit
E = I R
- Formula to calculate terminal potential difference
V = E - IR
[ where V is terminal potential difference , E is the Emf , R is resistance and I is current across the battery or cell ]
Solution :-
Calculating total resistance in the circuit
Resistors of 4.5 Ω and 9 Ω resistances are connected in parallel so, Equivalent resistance will be
➠1/Rₑ = 1/4.5 + 1/9
➠1/Rₑ = (2+1)/(9)
➠1/Rₑ = 3/9
➠ Rₑ = 3 Ω
Now,
ammeter and cell are connected in series
so, total resistance in the circuit will be sum of Rₑ , resistance of ammeter (R₁) and resistance of cell (R₂).
➠R = Rₑ + R₁ + R₂
➠R = 3 + 1.2 + 0.8
➠R = 5 Ω
Therefore,
total resistance in the circuit is 5 Ω.
Calculating total current in the circuit
using formula
➠E = I R
➠I = E / R
➠I = 2 / 5
➠I = 0.4 A
therefore,
- total current in the circuit is 0.4 A.
Calculating the potential difference through the 4.5 Ω Resistor
we calculated
Rₑ = 3 Ω as the equivalent resistance of 4.5 Ω And 9 Ω Resistor and the total current through the circuit is calculated to be 0.4 A
so,
➠P.d. across Rₑ = (0.4) (3)
➠P.d. across Rₑ = 1.2 V
Now, since resistances 4.5 Ω and 9 Ω Are in parallel therefore, potential difference through Rₑ = potential difference across 4.5 Ω Resistor = potential difference across 9 Ω Resistor.
therefore,
- potential difference across 4.5 Ω Resistor will be 1.2 V.
Calculating terminal potential difference of the cell
Using formula
➠V = E - IR
( taking R = resistance of cell, I is current through cell, E is Emf of cell , V is terminal potential difference )
➠V = 2 - (0.4)(1.2)
➠V = 2 - 0.48
➠V = 1.52 V
therefore,
- Terminal potential difference across the cell is 1.52 V.
Answer:
The kidneys are a pair of organs that are found on either side of the spine, just below the rib cage in the back. Kidneys: filter waste materials out of the blood and pass them out of the body as urine. regulate blood pressure and the levels of water, salts, and minerals in the body.