What is the cause of resistance class 12?
On a microscopic level, electrons moving through the conductor collide (or interact) with the particles of which the conductor (metal) is made. When they collide, they transfer kinetic energy. The electrons therefore lose kinetic energy and slow down. This leads to resistance.
What are the causes of resistance in a conductor?
As electrons move through a metal conductor, some collide with atoms, other electrons or impurities. These collisions cause resistance and generate heat. Heating the metal conductor causes atoms to vibrate more, which in turn makes it more difficult for the electrons to flow, increasing resistance.
What causes resistance physics?
Resistance is the hindrance to the flow of charge. For an electron, the journey from terminal to terminal is not a direct route. Rather, it is a zigzag path that results from countless collisions with fixed atoms within the conducting material. The electrons encounter resistance – a hindrance to their movement.
What are 4 factors that affect resistance?
There are 4 different factors which affect resistance:
- 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.
What are the two factors that influence resistance?
There are several factors that affect the resistance of a conductor;
- 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.
What affects a material’s resistance?
How much resistance a material has depends on several factors: the type of material, its width, its length, and its temperature. Materials such as metals have low resistance to electric current. They are called electric conductors. A wide wire has less resistance than a narrow wire of the same material.
What is resistance and what factors affect it?
Resistance is the property of the material that restricts the flow of electrons. There are four factors affecting resistance which are Temperature, Length of wire, Area of the cross-section of the wire, and nature of the material. The property of a material that restricts the flow of electrons is called resistance.
What would be a situation where a lot of resistance in a device is useful?
For example, a resistor can be used to transfer electrical energy into light (light bulb) or into heat (kettle element). Energy is wasted as it is lost to the surroundings. Resistors are used to provide useful energy transfers.
How are current voltage and resistance related?
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.
What happens to current if resistance increases?
This equation, i = v/r, tells us that the current, i, flowing through a circuit is directly proportional to the voltage, v, and inversely proportional to the resistance, r. But, if we increase the resistance, then the current will decrease.
What happens to resistance when voltage increases?
In a series circuit the components are connected along a single path. Therefore, if the voltage is increased, the current will increase provided the resistance of the circuit does not change. Similarly, increasing the resistance of the circuit will lower the current flow if the voltage is not changed.
Does resistance depend on voltage?
Hence, it can be concluded that the resistance value neither depends upon the voltage applied across the wire nor the current flowing through it. Resistance is the property of the material and does not depend upon current and potential difference.
Does voltage increase when resistance increases?
Resistance doesn’t increase directly because of Voltage. Increasing the voltage for a circuit with a given resistance increases the current flow.
Why is resistance directly proportional to voltage?
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.
What happens to voltage when resistance decreases?
This means that if the voltage is high the current is high, and if the voltage is low the current is low. Likewise, if we increase the resistance, the current goes down for a given voltage and if we decrease the resistance the current goes up.
Is resistance is directly proportional to voltage?
Ohm’s law Equation tells us that the current in a circuit can be determined if the values of resistance and voltages are known. Therefore, voltage is not proportional to resistance.
Is resistance directly proportional to temperature?
The resistance increases as the temperature of a metallic conductor increase, so the resistance is directly proportional to the temperature.
Is resistance directly proportional to length?
The resistance of a wire is directly proportional to its length and inversely proportional to its cross-sectional area. Resistance also depends on the material of the conductor.
What is resistance when length is doubled?
What happens to resistance when length is doubled? From the equation, we understand that resistance is directly proportional to the length of the conductor and inversely proportional to the crossectional area of the conductor. Doubling the length doubles the resistance.
Which is directly proportional to the resistance?
The resistance of any conductor is directly proportional to length and inversely proportional to area of cross-section of the substance. As value of resistance(R) is directly proportional to length of resistance, so by increasing the length of resistance the value of resistance increases.