Displacement current is that current which appears in a region in which the electric field (and hence electric flux) is changing with time. Note- We have ID = dΦ/dt = /dt = /dt = dq /dt = I ε0 ε0d(EA) ε0d[(q/ ε0A)A] 2. Modified Ampere’s circuital Law = (I + ) dΦ/dt µ0 ε0 ∮B.dl 3. Learn only one order either increasing wavelength or frequency .other calculated by c= ν λ ,velocity of light c=3x108m/s S.No. Name Frequency Wavelength Production Uses Range (Hz) Range 10-11 to 10- In medicine, to 1. Gamma rays 1019 – 1023 Emitted by radioactive nuclei, destroy cancer Produced in nuclear reaction cells. 2. X – rays 1016 - 1020 10-8 to Generated by bombarding a Used as metal target by high energy diagnostic tool electron in medicine, to study crystal structures 3. Ultraviolet 1015 – 1017 Produced by special lamps & For eye surgery, (4 10-7 to × to kill germs in rays very hot bodies (sun). 6 × 10-10) m water purifiers. 4. Visible rays 700 – 400 Jumping of electrons in higher Provide us × 1014 – × nm orbits information 1014 about the world. Infrared 1mm - 700 Produced by hot bodies and Infrared 5. 1012 - 1014 rays (heat nm molecules. detectors used waves) in earth satellite, used in green house to keep plants warm. 6. microwaves 1010 - 1012 0.1 – 1 mm Produced by special vacuum Microwave tubes (klystrons, gun diode & oven, for radar magnetrons) system in aircraft navigation. Produced by accelerated In radio & 7. Radio waves 10 - 109 > 0.1 m motion of charges in conducting television wires. communication system, in
Displacement current is that current which appears in a region in which the electric field (and hence electric flux) is changing with time. Note- We have ID = ε0 dΦ/dt = ε0d(EA) /dt = ε0d[(q/ ε0A)A] /dt = dq /dt = I 2. Modified Ampere’s circuital Law ∮B.dl = µ0 (I + ε0 dΦ/dt ) 3. Learn only one order either increasing wavelength or frequency .other calculated by c= ν λ ,velocity of light c=3x108m/s S.No. Name Frequency Range (Hz) Wavelength Range Production Uses 1. Gamma rays 1019 – 1023 10-11 to Emitted by radioactive nuclei, Produced in nuclear reaction In medicine, to destroy cancer cells. 2. X – rays 1016 - 1020 10-8 to Generated by bombarding a metal target by high energy electron Used as diagnostic tool in medicine, to study crystal structures 3. Ultraviolet rays 1015 – 1017 (4 × 10-7 to 6 × 10-10) m Produced by special lamps & very hot bodies (sun). For eye surgery, to kill germs in water purifiers. 4. Visible rays × 1014 – × 1014 700 – 400 nm Jumping of electrons in higher orbits Provide us information about the world. 5. Infrared rays (heat waves) 1012 - 1014 1mm - 700 nm Produced by hot bodies and molecules. Infrared detectors used in earth satellite, used in green house to keep plants warm. 6. microwaves 1010 - 1012 0.1 – 1 mm Produced by special vacuum tubes (klystrons, gun diode & magnetrons) Microwave oven, for radar system in aircraft navigation. 7. Radio waves 10 - 109 > 0.1 m Produced by accelerated motion of charges in conducting wires. In radio & television communication system, in 10-
physics-xii-15-16.docx