What happens to current when temperature increases?
The resistance of a conductor increases as temperature increases. So Ohm's Law I = V_S / R means that current decreases as temperature increases.
Does power increase with current density?
No.For a specified circuit, the current /power will change only if the load / resistance changes, or because of the effect of temperature on the materials and that too within a specified (perhaps) range.Again, the material composition of the components only will dictate whether the current density will increase with the increase in power, as, in a specified circuit; the material composition will not materially change ?Physics equations/Current and current density
Why does resistance increase with a decrease in density?
Resistivity of a conductor is given by the formula, p = m/ne^2λwhere m = mass of electron n = number density of free electron e = charge of an electron λ = relaxation time(1) it is evident from the formula given by equation that the resistivity of a conductor is inversely proportional to the number density 'n' of free electrons(2) the resistivity of a conductor is inversely proportional to the relaxation time λ.'Density'Free Electron Density in a conductor:Suppose, metals will have free electron density n = x 10^ /m^3 and will have a number of atoms per unit volume n' = x 10^ /m^3. The number of atoms per unit volume multiplied by the number of free electrons per atom should agree with the free electron density above. Now, solid copper is more dense than gaseous copper. However gaseous copper is an extremely poor conductor than solid copper.http://hyperphysics.phy-astr.gsu...
Why does the density of saturated vapor increase with increasing temperature, while that of saturated liquid decrease with increasing temperature?
It's because at higher temperature the liquid that is sitting below the saturated vapor is able to eject more molecules of vapor out into the gas at higher temperature. It's cramming more gas into the available volume. Don't think of the saturated gas as a gas with a fixed mass in a fixed volume that you are increasing the temperature of. It's more like you are adding mass to the fixed volume as the temperature goes up, so the density goes up (and so does the pressure, which in this case is called the saturated vapor pressure).
How do i tell if the density of these objects increase, decrease or stay the same?
solid objects are incompressible ...so as for ant solid object if temperature is fixed density is fixed,if an iron bar is cooled its length decreases increasing its density but this effect is very little... if Cl gas is compressed volume is decreased radically increasing the density... if diamond is submerged into water no physical or chemical changes occur keeping the density same .. if a lead is carried up the mountain density remains same if we ignore temperature drop ....
The combination of the low temperature and increased salinity results in the underlying seawater having?
It is high, but not for the reason you stated. Water is at it's highest density at about 4 deg. C. It is not frozen. Once it freezes, it becomes much less dense, so ice floats on liquid water. When water has a high amount of dissolved solids in it, the solution has a higher density than pure water.
It is said that velocity of sound increases as the temperature increases, but when the temperature increases the substance expands and molecular space increases so wavelength also increases, how can the velocity increase as the temperature increases?
Two things: The speed of sound in air is approximately proportional to the square root of the absolute temperature (over a fairly wide range of temperatures). The reason is that it is inversely proportional to the square root of the mass density of the air, which decreases as the temperature increases and the air expands. When expressed in terms of just the temperature, it reduces to the following equation for dry air:where 331 m/s is the speed of sound at 0° C and T is the temperature in Kelvin. (The 273 inside the square root sign is just the kelvin equivalent of 0°C.) And this is consistent with the measured speed of sound in air. (For example, measuring the speed of sound in air at 20°C, or 293 K, yields a speed of sound of 343 m/s.)But the speed of any wave motion (sound, light, seismic waves, water waves, it doesn’t matter) is given by the product of the frequency and the wavelength. That is,The frequency of a sound wave does not change just because the temperature of the air through which it propagates increases, so that means that as the wave speed increases with increasing temperature, so does the wavelength.
How temperature is related to density?
As a common rule of thumb, for most pure liquids temperature is inversely proportional to the density. That is, temperature rise lowers the density, and lowering temperature will increase density. This rule is true for all liquids that shrinks on solidification with exception of water, which expands on solidification. Therefore, if you lower water’s temperature, it’s density will increase until temperature reaches to 4 Deg C. After that water’s density falls as it freezes at 0 Deg C. That’s why ice floats in water because it’s lighter than water.
9. Explain the roles of density and temperature in convection.?
When the TEMPERATURE of a gas(liquid) increases, the volume increases too, therefore the DENSITY decreases (mass remains constant) and the warm gas(liquid) rises. That's how heat is transferred by CONVECTION.