The resistance of two resistors respective 20ohm and 4ohm are connected with a 6V battery. Find the resistance, current and voltage across lamp&conductor.
Answers
Explanation:
a). the total resistance of the circuit =20Ω+4Ω=24Ω
b). The current through the circuit= current through the bulb= current through the conductor.
The current through the circuit=
the voltage of the battery
voltage applied
.
the current through the circuit =
24
6
amp
The current through the circuit = 0.25amp
c). The potential difference across the lamp and the conductor.
(i) The potential difference across the electrical lamp =0.25×20=5volt
(ii) The potential difference conductor =0.25×4=1 volt
d). Power can be calculated as
current through the lamp
voltage across the lamp
power=
0.25
5
→20W.
Answer:
Energy dissipated = PtorVI×tor =I
2
Rt Joules
Consider Ohm's law V=IR.
In this case the resistors are connected in series and hence, the total resistance is 4+2=6 ohms. In a series circuit, the current remains the same throughout the circuit and so we use the I
2
Rt Joules formula.
The total current in the circuit is calculated as I=V/R=6/6=1ampere.
Therefore, the power dissipated P across the 4 ohm resistor for 5 s
= 1
2
×4×5=20Joules
Hence, The heat dissipated by the 4 resistor in 5 s will be 20 J.