Hi there.

Just a noob in electronics. I have been reading lots of tutorials and trying to learn more and more about electrical circuits.

Generally speaking, are resistors and Relays opposite to each other?

i think this because resistors control (lessen) the flow of current in the circuit and relays enhance the voltage and current in the circuits using electromagnetic field.

Is this right? Or am i missing something?

 

The two components are not really related. A resistor affects current in a circuit according to Ohm's law - E = IR. So current in a DC circuit is completely dependent on the value of R. In an AC circuit, you have impedances that also act as resistances, but that's a different question. Resistors use some inherently resistive substance to arrive at their value of resistance. Electromagnetism is not involved.

A relay is an electromechanical switch. Placing a voltage across the coil results in a current that creates a magnetic field that pulls the armature and closes the contacts. That, in turn, can complete a separate circuit. It is most accurately viewed as a remotely controlled switch.

 

And another way to look at a switch is a resistor whose resistance is either 0 or infinity.