How to test if a substance is salt or sugar?
The quickest test you could do would be to warm a little with ethanol. The sugar will dissolve easily whereas salt is insoluble. You could also do a melting point. Sucrose (table sugar) melts with slow decomposition at 186deg.
What do you understand by the resistivity of a substance?
Resistivity or specific resistance of a body is a characteristic by which one can judge the electrical property of a substance. As the name suggests, resistivity is associated with the resistance to electrical flow of electrons. Resistivity quantifies how strongly a material opposes the flow of electrons through it.If a material has low resistivity, it means it offers less resistance to the electric current. This implies that a material with low resistivity has highly conductive. For example, Silver!In terms of definition, resistivity is defined as the resistance of a of a material of unit cross section and unit length.We know that resistance can be written as:R = ρ L/AWhere ρ is a the resistivity of the substance.This clearly means that.. resistivity of a substance is moreover same for any length or cross section area, whereas the resistance can vary!Therefore resistivity is an intrinsic property of a material!Hope that helps!
Why does a thin wire have a high resistance to the flow of current through it?
During summer vacation, Your all family cousins come at your place. Let assume the total number is 10. You told them to go at roof and play there. Everyone starts running toward the stairs and try to get first on the roof. But stairs have limited space, 2 people can easily climb up. What will happen If the breadth of staircase is increased. Everyone can easily go at roof at a same time, without fighting with each other.Same thing with the wire. You all are the electrons, breadth of the staircase is thickness of the wire. And all want to reach the roof first.Because of less space for motion/drifting of electrons, they find it difficult to move and hence produce resistance as friction in your case..!!
What is the Difference between Conductors and Insulator?
In conductors there are a "sea of electrons" which are free to move about from atom to atom. Insulators have tightly bound electrons, so it is not possible to get a current through the material. Electrical insulation is the absence of electrical conduction. Electronic band theory predicts that a charge will flow whenever there are [energy] states available into which the electrons in a material can be excited. This allows them to gain energy and thereby move through the conductor (usually a metal). If no such states are available, the material is an insulator. An intermediate material such as Nichrome wire (80% nickel, 20% chromium) will permit some flow of electrons, but the resistance is very high, so most of the electrical energy is dissipated as heat.
Why are conductors low in resistance?
The substances that allow the flow of electricity are termed as conductors.As a conductor consists of free electrons, these free elctrons move in a disciplined constituting the flow of current.Resistance is defined as the opposition to the flow of electrical current through a conductor.It’s important to point out that conductivity and resistivity (the property that determines final resistance) are inversely proportional.The more conductive something is, the less resistance it will have.Hope it helps, thank you for reading.
How does the thickness of a fluid compare to it's viscosity?
If the oil in your car has too little viscosity, it will easily flow out of the gaps between surfaces and will not lubricate them well. Those surfaces will experience sliding friction and wear. If the oil has too much viscosity, it will waste the engine's energy by opposing motion and turning work into thermal energy. Modern motor oils have carefully adjusted viscosities that balance the two problems. Since temperature affects viscosity (e.g., hot molasses has less viscosity than cold molasses), motor oils add chemicals that stabilize their viscosities over wide temperature ranges. When a fluid is subjected to external forces, it resists flow due to internal molecular friction. Viscosity is a measure of that internal friction. Viscosity can be referred to as the measurement of a fluid’s resistance to flow.
A few Biology Questions....?
1. What bio molecules are used to extract a gene from a chromosome? 2. Explain why the same restriction enzyme must be used to extract the gene and open the loop of DNA in the bacterium. 3. What substances should be added to a bioreactor to enable bacteria to grow? 4. Give one advantage of using genetically engineered insulin compared with that of extracted from pigs, sheep or cattle. 5. Explain how cloning would be used to produce large numbers of herbicide-resistent plans. 6. What is a DNA ligase?