When a 22 ohms resistance is connected across its terminals a potential difference 2.2V is produced. Find the internal resistance and lost volt of the cell... Please solve this sum..This sum is from Current Electricity chapter...Class 10..Please I will mark you brainliest if you solve this sum...
Answers
Final Answer : 1.95V
Underst\nding :
1) Potential Difference across terminal of a cell,
V = E - I r
where
E = EMF of cell =2V
r = internal resistance =0.1ohm
i = current in circuit.
R = External Resistor
Steps :
1) Cell and External resistor are connected directly,
=> R(eq) = r + R
=0.1 + 3.9 = 4.0 oh m
2) Current in circuit,
I = E / R(eq)
= 2/4.0 = 1/2 =0.5 A
3) Potential Difference across terminal of a cell,
V = E - Ir
= 2 - 0.5 *0.1
= 1.95 V.
See Circuit Diagram in pic
Explanation:
P.D.=2.2volts , this is the EMF of the cell.
Now when the circuit is closed and a current is flowing through the circuit then the P.D.=1.8V
Thus the total resistance of the circuit is R+r=5+rohms
So, the current in the circuit is i=(
5+r
2.2
hence the PD across the internal resistance.
Given that,
5+r
2.2
)=2.2−1.8 as the drop in the potential across the battery is due the P.D. across the internal resistance.
So,
r(
5+r
2.2
)=0.4
1.8r=2
r=1.11ohms
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