The resistance is proportional to the voltage or pressure drop for a given current . In the hydraulic example, the resistance can be increased by for example reducing the diameter of the constriction. For a resistor or wire, the resistance is in general dependent on the material and the geometrical shape.
What affects the resistance of a resistor?
The type of material of which the resistor is made. The length of the resistor . The thickness of the resistor . The temperature of the conductor .
How is the resistance of a resistor increased?
The resistance of all materials changes as their temperature changes. ... Increasing the temperature (typically) increases resistance. The temperature coefficient of resistance (TCR) of wire or a resistor relates the change in resistance to the change in temperature.
How does the resistance of a resistor change with voltage?
Ohms law states that the current flowing in a circuit is proportional to the voltage applied to the circuit, and inversely proportional to the resistance of the circuit. In other words, for a given voltage, the current in the circuit will decrease as the resistance increases .
How do you change the resistance in a circuit?
- material, eg copper, has lower resistance than steel.
- length – longer wires have greater resistance.
- thickness – smaller diameter wires have greater resistance.
- temperature – heating a wire increases its resistance.
Does a resistor have a constant resistance?
If a resistor obeys Ohm’s law the resistance is constant (i.e. independent of voltage and current) by definition.
What does resistor resistance indicate?
Resistors are electronic components which have a specific, never-changing electrical resistance. The resistor’s resistance limits the flow of electrons through a circuit . They are passive components, meaning they only consume power (and can’t generate it).
Does higher resistance mean higher voltage?
The current is directly proportional to the voltage and inversely proportional to the resistance. This means that increasing the voltage will cause the current to increase , while increasing the resistance will cause the current to decrease.
What happens to resistance if voltage increases?
In a series circuit
Why does voltage increase when resistance increases?
In other words, the current is directly proportional to the voltage and inversely proportional to the resistance. So, an increase in the voltage will increase the current as long as the resistance is held constant . ... If the current is held constant, an increase in voltage will result in an increase in resistance.
Is always connected in series with resistance?
Ammeter is an instrument for measuring either direct or alternating electric current passing through a circuit, in amperes. ... An ammeter is always connected in series in a circuit because its resistance is very low . So, the correct answer is “Option B”.
What happens if you change the resistance in a circuit?
Ohm’s law defines the relationship between the voltage, current, and resistance in an electric circuit: i = v/r. ... This means that increasing the voltage will cause the current to increase , while increasing the resistance will cause the current to decrease.
Are resistance and current directly proportional?
The relationship between current, voltage and resistance is expressed by Ohm’s Law. ... This states that the current flowing in a circuit is directly proportional to the applied voltage and inversely proportional to the resistance of the circuit, provided the temperature remains constant.
Why does the resistance do not remain constant when voltage increases?
Answer: Ohm’s law states that the electrical current (I) flowing in an circuit is proportional to the voltage (V) and inversely proportional to the resistance (R). Therefore, if the voltage is increased, the current will increase provided the resistance of the circuit does not change.
What does constant resistance mean?
A form of dynamic resistance exercise in which the load does not vary during the exercise . Constant resistance exercises use simple equipment, such as free weights, which can be moved by concentric and eccentric muscle actions.
Does a light bulb have a constant resistance?
The filament in an incandescent bulb does not have a constant resistance . If you take a bulb and increase the voltage across it, the current increases too. An increase in current means the bulb gets hot—hot enough to glow. As the temperature increases, however, the resistance also increases.
