uses of resistance

Asked by Shivraj Raghu | 8th May, 2013, 11:17: AM

Expert Answer:

1. Uses of resistance - Resistance in any electric wire helps in manipulating the current that is flowing through the circuit. Also, it enables the measurement of current and voltage flowing through a circuit. Furthermore it sometimes helps in saving electric appliances from excess current as the excess current would produce greater heat in the presence of resistance leading to breakdown of circuit at that point. 
 
2. Q = I x t = 0.25*2*3600 = 1800 C
 
3. Electric current I = q/t. As both charge and time are scalars, therefore electric current is a scalar quantity. Furthermore, electric current in a wire by an arrow to indicate the direction of flow of positive charge. But such arrows are not vectors because they do not obey the laws of vector algebra. When a current divides in the 2 arms, then the resultant current is just the addition of the current in the 2 arms and has nothing to do with the angle between those arms. So, electric current is a scaler quantity. 

Answered by  | 8th May, 2013, 07:06: PM

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