Why resistivity does not depend on length and area?
Larger cross sections have less resistance, and longer conductors have more resistance. Therefore, by multiplying resistance by area and dividing by length, you get a value for a material property (resistivity ρ) that doesn’t depend on the size of the conductor.
Which will produce more heat Nichrome or copper?
Nichrome and copper wires of same length and same radius are connected in series. Current is I passed through them. Thus nichrome wire will produce more heat.
What is resistance change?
Resistance to change is the unwillingness to adapt to altered circumstances. It can be covert or overt, organized, or individual. Employees may realize they don’t like or want a change and resist publicly, and that can be very disruptive.
Is resistivity directly proportional to resistance?
Resistivity ρ is an intrinsic property of a material and directly proportional to the total resistance R, an extrinsic quantity that depends on the length and cross-sectional area of a resistor. The resistivity of different materials varies by an enormous amount.
What is the resistivity of alloys?
Resistivity (ρ) & Conductivity (σ) of Metals, Alloys, Rocks, and Soils
| Metal & Alloy Materials | Form | Resistivity (x10-6 Ω·cm) |
|---|---|---|
| Aluminum | liquid solid | 20.3 2.62 |
| Antimony | liquid solid | 123 39.2 |
| Arsenic | solid | 35 |
| Beryllium | solid | 4.57 |
Do alloys have low resistivity?
Alloys and metals have free electrons that can flow easily in the conductor. The atoms of alloys and metals have large free space which allows the current to flow through the conductor. Thus, Metals and alloys have very low resistivity.
What factors does resistance depend on?
The resistance of a conductor depends on the cross sectional area of the conductor, the length of the conductor, and its resistivity. It is important to note that electrical conductivity and resistivity are inversely proportional, meaning that the more conductive something is the less resistive it is.
What are the 4 factors that affect resistance?
Factors That Affect Resistance How much resistance a material has depends on several factors: the type of material, its width, its length, and its temperature.
Is resistivity directly proportional to area?
The resistivity of the conductor is inversely proportional to the area of the conductor.
On what factors resistance and resistivity depends?
Resistance of a conductor depends on length of the conductor and area of cross section of the conductor, resistivity and temperature. Resistivity is a materialistic property depends on the material and temperature of the conductor.
Does resistivity depend on length?
The resistivity of a material is the resistance of a wire of that material of unit length and unit cross-sectional area. The unit for resistivity is the ohm-metre. The resistivity of a material depends on its nature and the temperature of the conductor, but not on its shape and size.
What is a specific resistance?
Specific resistance is defined as the resistance offered per unit length and unit cross-sectional area when a known amount of voltage is applied.
What material has the highest electrical resistance?
silver
What is resistivity of any solution?
Resistivity of any solution : When current flow in the solution through two electrodes resistance is proportional to length and inversely proportional to cross sectional area A. The constant p(rho) is called resistivity or specific resistance. Thus, Resistivity of any solution is the resistance of one cm cube.
Why do alloys have high resistivity?
Free electrons are scattered off imperfections and alloys have many more of them than pure metals. The higher resistivity in alloys as compared to the constituents is caused by an additional scattering mechanism of the electrons called “alloy scattering”. So there is a small relaxation time and hence large resistivity.
Why manganin wire is used in meter bridge?
In a metre bridge, wires of nichrome, manganin and constantan are used because it has high resistance and low-temperature coefficient of resistance.
How does current affect resistance?
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.
Which conductor has less resistivity?
The Resistivity of Various Materials A material with low resistivity means it has low resistance and thus the electrons flow smoothly through the material. For example, Copper and Aluminium have low resistivity. Good conductors have less resistivity. Insulators have a high resistivity.
What is the difference between resistance and resistivity?
Resistance is the physical property of a substance because of which it opposes the flow of current i.e. electrons. Resistivity is the physical property of a particular substance which is having particular dimensions. Resistivity is only proportional to the nature and temperature of the particular material.
What is resistance measured in?
Resistance is a measure of the opposition to current flow in an electrical circuit. Resistance is measured in ohms, symbolized by the Greek letter omega (Ω). Ohms are named after Georg Simon Ohm (1784-1854), a German physicist who studied the relationship between voltage, current and resistance.
Which has more resistivity copper or manganin?
Manganin is an alloy of Cu with manganese and nickel. Since the latter two metals have resistivity greater than copper, the pure copper has lower resistivity and the manganin thus has to be thicker to have the same resistance.
What is the formula of resistivity?
Resistivity, commonly symbolized by the Greek letter rho, ρ, is quantitatively equal to the resistance R of a specimen such as a wire, multiplied by its cross-sectional area A, and divided by its length l; ρ = RA/l. The unit of resistance is the ohm.
What happens to resistivity when length is doubled?
Answer: the resistance of a conductor is directly proportional to its length. so if length is increased then resistivity increases ande vice versa. so if length is doubled resistance will also get doubled i.e resistance is 4 times that of original resistance.