The brightness of the lamp is proportional to the current flowing through the lamp: the larger the current, the brighter the lamp.
The current flowing through the lamp is given by Ohm's law:
where
V is the potential difference across the lamp, which is equal to the emf of the battery, and R is the resistance of the lamp.
The problem says that the battery is replaced with one with lower emf. Looking at the formula, this means that V decreases: if we want to keep the same brightness, we need to keep I constant, therefore we need to decrease R, the resistance of the lamp.
The least number of component of a vector quantity is two. These are the x-component and the y-component.
The resultant vector, or vector as we refer to it in this item, can be calculated through the equation,
RV = sqrt ((Vx)² + (Vy)²)
From the equation, it can be noted that if we let Vx equal to zero,
RV = Vy
Similarly, if we let Vy be equal to zero then,
RV = Vx
Thus, it is still possible for the vector to become nonzero even if one of its components is zero.
Significant digits show the precision of measurements and calculations
I Think Its True My Dude Or Dudette
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Hope this helps
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Zane
