What is the relation between wavelength and refractive index?
The refractive index can be seen as the factor by which the speed and the wavelength of the radiation are reduced with respect to their vacuum values: the speed of light in a medium is v = c/n, and similarly the wavelength in that medium is λ = λ0/n, where λ0 is the wavelength of that light in vacuum.
Why does refractive index not have a unit?
Answer. The refractive index has no units because the units cancel out when calculating the value. The refractive index is calculated by dividing the speed of light in a vacuum by the speed of light in the new medium.
What is an ohm in SI units?
The ohm (symbol: Ω) is the SI derived unit of electrical resistance, named after German physicist Georg Ohm.
What happens when the 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.
What are the 3 factors that can affect the value of wire’s 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 will be the change in frequency of wire if its length is doubled?
The length and diameter of a metal wire is doubled the fundamental frequency of vibration will change from n to (tension being kept constant and material of both the wires is same) For the wire ,T and ρ are the same .
What will be its resistance when its length becomes 2 Lo?
If the original length of the wire is l and its cross-sectional area is A, then its resistance, R=ρl/A. When the length becomes 2l, cross-sectional area reduces to A/2 because volume of the wire does not change. Changes resistance, R′=ρ(2l)(A/2)=4ρlA=4R.
What is the effect of length on resistance?
The resistance of a long wire is greater than the resistance of a short wire because electrons collide with more ions as they pass through. The relationship between resistance and wire length is proportional .
What is the relationship between temperature and resistance?
As temperature rises, the number of phonons increases and with it the likelihood that the electrons and phonons will collide. Thus when temperature goes up, resistance goes up. For some materials, resistivity is a linear function of temperature. The resistivity of a conductor increases with temperature.