| defect of the eye where it can only see distant objects clearly.
convex lens
1/f=1/D-1/d | hypermetropia |
| defect of the eye where it can only see the nearer objects clearly.
concave lens of focal length equal to the far point . | myopia |
| the splitting for white light into seven colours on passing through a refracting medium, violet disperses more | dispersion |
| temperature coeff of resistance | it is defined as the ratio of increase in resistance per degree centigrade rise in temperature to its resistance at 0C |
| gauss law for magnestism | states that no magnetic monopoles exists and that the total flux through any closed surface must be zero. |
| angle of declination | the angle between the magnetic meridian and the geographical meridian |
| angle of inclination/angle of dip | the angle made by the total strength of the earths magnetic field with the horizontal line of magnetic meridian |
| lenz's law | the direction of induced emf is such that it tends to oppose the change in magnetic flux that produced it. |
| faraday's law of electromagnetic induction | the emf induced in a conducting loop is equal to the rate at which the magnetic flux in the conducting loop changes with time |
| power factor | the cosine of the phase angle between the voltage and current in an ac circuit.
cos=R/Z |
| uses of IR rays | molecular structure
night time photography
solar cookers/heaters
physiotherapy |
| uses of microwaves | radar systems
long distance com
ovens |
| production of microwaves | by special vaccum tubes like klystron, maagnetron, gunn diode |
| coercivity | is the intensity of the magnetic field applied to reduce the magnetization to zero |
| retentivity | it is the capability to retain magnetism after the magnetization force has been ceased |
| work function | the minimum amount of energy of incident photon required to eject electrons from the surface of a photometal |
| photoelectric effect | the phenomenon of emission of electrons from the surface of a metal ,when a radiation of suitable frequency is incident on it |
| photosensitive substances | alkali metals because their work function is low |
| isobars | same atomic number but different atomic mass |
| isotopes | same mass number ,diff atomic number |
| istones | same neutron number , different atomic number |
| amplifier | the device used to rise the strength of a weak signal |
| mobile phone | space wave com |
