Page 104 - Physics 10_Float

CURRENT ELECTRICITY

1 1 1 1 1 1 1 1
= + + = + + x For your information
R e 2Ω 3Ω 6Ω 2 3 6 Ω If the values of all the resistors
in a parallel circuit are the
1 6
= same, the overall resistance
R e 6Ω can be determined by
or R = 1Ω 1 N
e
This value is smaller than the lowest value of the resistance in R = R
the combination which is always the case in parallel circuits. e R
(b) In parallel combination, the potential difference across i.e., R = N
e
each of the resistance is same and is equal to the potential of
the battery, which is 6 V. Therefore, where N is the total number of
resistors and R is the resistance
V 6 V of each individual resistor.
Current through R is I = = = 3 A
1
1
R 1 2 Ω
V 6 V
Current through R is I = = = 2 A
2 2
R 2 3 Ω
V 6 V
Current through R is I = = = 1 A
3 3
R 3 6 Ω
(c) Sum of the currents passing through the resistances in For your information
parallel combination is equal to the total current I of the Typical power ratings
circuit. Therefore, total current is 6 A. Power
Appliance
Activity 14.2: Connect a battery to a small 2.5 V light bulb and (watts)
observe the brightness of the bulb. Connect a second light Electric stove 5,000
bulb in parallel with the first and observe the brightness of Electric heater 1,500
the bulbs. Now add a third bulb in parallel with the others and Hair dryer 1,000
Iron 800
note the brightness of the bulbs. Does the brightness of the
Washing
bulbs differs from the bulbs connected in the series with the machine 750
battery? Explain. Light bulb 100
Small fan 50
14.10 ELECTRICAL ENERGY AND JOULE'S LAW Clock radio 10

Turbine runs generator to produce electrical energy when
water falls on it from higher gravitational potential to lower
gravitational potential. Similarly, when charge moves from a
higher electric potential to a lower potential, it delivers
electric current. Thus, the process during which charges
continuously move from a higher potential to a lower

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