as a physics student you know that with the increase in resistance (force that opposes flow of current)there is decrease in current.
the adjustable resistance is known as rheostat.
if you want to adjust amounts of current passing through the circuit we place rheostat in circuit to adjust resistance
if we want same amount of current to be flow on circuit we can use resistance
to verify different laws also we use rheostat
to verify this law different resistances is adjusted so that to see the amount of flow of current and see the value v=-ir is correct or not
A rheostat is a variable resistor. The resistance in the circuit can be varied at our will. Hence the current too. It has got two fixed terminals and a variable terminal (a sliding contact) in between. Only to vary the current / resistance with any one of the fixed terminals the sliding terminal can be used. With a fixed potential source, if we are using all the three terminals suitably connected, a potential deviding arrangement can be set up. ( I'm sorry , a circuit diagram can not be drawn in this format)
A rheostat controls the amount of current flowing in the circuit.
rheostat contols the resistance in circuit.
in circuit to avoid exceesive flow of current resistance is required which prevents overloading of current and also shortcircuiting which is done by rheostat.
It provides a means of adjusting current flow in a circuit by altering a variable resistor that is in the circuit.
a rheostat just reduces the current---see your first answer. *If* you are willing to do the work of checking the temperature, and changing the setting , *Often*, Sometimes several times a day. They work OK, and are cheaper, and easier to find, than a thermostat. ( Light dimmer switches are rheostats.) But, you can't go out of town, in case of a heat-wave or cold spell, you ought to get up and check the temp at night, etc Oh, and Test run the thing for a week or so, to see how the heat builds up--how long it takes to get warm or cool down i would go with the thermostat, myself
it serves two purposes:-
1) maintains a potential difference b/w two points so that current can flow.
2) also controls the flow of current
control the flow of current