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If the current flowing through a device is doubled while resistance remains constant, the power consumed becomes:
Double
Half
Four times
One-fourth
Four times
The power consumed by a device is directly proportional to the square of the current flowing through it when resistance remains constant. Since the current is doubled, the square of the current becomes 22=4 times the original value, making the power four times greater.
The power consumed by a device is directly proportional to the square of the current flowing through it when resistance remains constant. Since the current is doubled, the square of the current becomes 22=4 times the original value, making the power four times greater.
Think of a water pipe where current is the speed of water and resistance is the pipe's narrowness. To push twice the amount of water through the same pipe against the same friction requires four times the effort (or energy), similar to how increasing electrical current increases heat dissipation exponentially.
P-I-S-R: Power is proportional to the Square of current (I) when Resistance (R) is fixed.
P=I2R тАФ Power in terms of current and resistance
P=V├ЧI тАФ General power formula
V=I├ЧR тАФ Ohm's Law
According to Joule's Law of heating and the power formula P=I2R, where P is power, I is current, and R is resistance, if R is constant and I changes to 2I, the new power PтА▓ becomes (2I)2R=4I2R=4P. This quadratic relationship occurs because power represents the rate of energy dissipation, which scales rapidly as current increases due to more frequent electron-atom collisions.
Power is proportional to the square of the current (PтИЭI2).
Joule heating leads to energy loss as heat, which increases significantly with higher current.
This principle is the reason high-voltage transmission lines are used to minimize power loss by reducing current.
Design of fuse wires in household circuits.
Heating elements in appliances like toasters and electric heaters.
The SI unit of power is Watt (W), equivalent to 1┬аJoule/second.
Option A is incorrect because it ignores the squared relationship.
Option B is incorrect because it suggests current and power are inversely proportional.
Option D is incorrect as it describes the relationship if current were halved.
C is correct тАФ Power is proportional to the square of the current, so doubling the current results in 22=4 times the power.
Always identify which variable is held constant before applying power formulas; if V is constant, P is inversely proportional to R, but if I is constant, P is directly proportional to R.