Compare the power used in the 2 Q resistor in each of the following circuits:
(1) a 6 V battery in series with 1 Q and 2 resistors, and
(10) a 4 V battery in parallel with 12 2 and 2 resistors.
Answers
Answer:
Compare the power used in the 2 Q resistor in each of the following circuits:
(i) a 6 V battery in series with 1 Ohm and 2 Ohm resistors,
➜Potential difference, V = 6 V
1 Ohm and 2 Ohm resistors are connected in series.
Therefore, equivalent resistance of the circuit,
R = 1 + 2 = 3 Ohm
According to Ohm’s law,V = IRWhere,I is the current through the circuitI= 6/3 = 2 A
This current will flow through each component of the circuit because there is no division of current in series circuits.
Hence, current flowing through the 2Ohm resistor is 2 A.
Power is given by the expression,P= (I)2R = (2)2 x 2 = 8 W
(ii) a 4 V battery in parallel with 12 Ohm and 2 Ohm resistors.
➜Potential difference, V = 4 V12 Ohm and 2 Ohm resistors are connected in parallel.
The voltage across each component of a parallel circuit remains the same.
Hence, the voltage across 2 Ohm resistor will be 4 V.
Power consumed by 2 Ohm resistor is given byP= V2/R = 42/2 = 8 W
: Therefore, the power used by 2 Ohm resistor is 8 W.