The currents produced in a The currents produced in a superconductor lead to superconductor lead to levitation of a magnet.levitation of a magnet.

When a superconductor is in an applied magnetic field, the field surrounds superconductor, but doesn’t penetrate.

Applied magnetic field induces a current, which produces a magnetic field that cancels applied magnetic field inside superconductor.

Magnetic field inside superconductor is always zeroMagnetic field inside superconductor is always zero

The interaction between magnets /magnetic fields and The interaction between magnets /magnetic fields and superconductors has been applied to develop the...superconductors has been applied to develop the...

Uses this interaction so it magnetically levitates or “floats” along and above the tracks.So, friction between the train and its tracks is virtually non-existent.

• very high speed

• reliability

• safety

• minimum maintenance

• low environmental impact

-uses attraction

- superconductors induce current in coils, producing electromagnets. Energised electromagnets attracted up to iron rails on guideway’s edges.

- electromagnets of like polarity are in guideway and train, these are repelled, lifting the train.

- other guidance magnets are embedded in train body, keeping it stable.

- uses repulsion

It uses the meissner effect, with superconducting magnets on the train and the electrically conductive strips or coils in the guideway.

The magnets and the coils act like two ‘like poles’ resulting in a repulsion between the two so the train is lifted off the guideway.

Achieved by continually changing polarity of alternate magnets along the track, creating a series of attractions and repulsions, providing accelerating force.

MRI machinesMRI machines::• Provide doctors with 3D images of internal structure of human body.

• Strong magnetic field provided by a superconductor applied to body.

• H atoms in body’s water and fat forced to accept energy then release it for computer processing.

Computers: powerful computers which are able to process all the data have had to be developed. Positively influenced, increased and furthered computer development.

Energy is not being lost, so once desired magnetic field strength is achieved no further energy imput is required (unlike normal solenoids). So this has a positive effect on electrical transmission, motors and generators. As relatively not much energy is required and heat is not being produced.

• extremely sensitive

• use Josephson effect to detect tiny magnetic fields

• used:-in geophysics

-to make magnetograms of brain/heart

Electrons able to travel across insulator, with superconducting material either side, as cooper pairs.

Can be used in superfast switches. Further improving computers as the superconducting switching devices can operate at speeds up to 10 times the speed of a semiconductor switch.

Other applications in the following areas are all advantageous, Other applications in the following areas are all advantageous, providing further developments and extremely positive effects on the providing further developments and extremely positive effects on the areas.areas.Electricity transmissions: energy losses caused by wire’s resistance. If superconducting wires used energy would be saved, 3-5 times more current carried, long distances not an issue- power stations in remote locations, reduced cost of power and demand for new power stations.

Motors and generators: superconducting wire is more efficient than copper wire.

- fraction of size and mass

- less fossil fuels required

Power storage: SMES means electricity doesn’t have to be used immediately. Stored in wires and no electrical heat energy will be lost.

Light gathering power of a telescope

OR

Its ability to pick up faint objects

Sensitivity depends upon collecting area of lens or mirror

Collecting area depends on diameter of lens or mirror

dd

Ability of telescope to distinguish between two very close objects.

• depends upon wavelength of light being collected and the size of the aperture- diameter of the lens or mirror.

Larger diameterLarger diameter more sensitive more sensitive improved resolutionimproved resolution

A good telescope design (large diameter lens or mirror), limits aberrations- faults/imperfections which cause a point object to appear as a “blob”.

A larger diameter objective lens or mirror is desirable- resolution is better, thus image is clearer.

Adaptive optics: measures and compensates for atmospheric effects. Incident light ray (e.g from a star) sampled- measuring atmospheric distortion. Information processed, mirrors adjusted, image is undistorted.

Active optics: measures and compensates for imperfections in mirror. Works slower than adaptive optics. Light sampled, signals sent and actuators on back of mirror push or pull it into the correct shape, correcting sagging and other deformaties.

Interferometry:‘unblurs’ images received by optical telescopes.

Uses 2/more telescopes and combines their signals.

Resolution power: Telescopes x distance apart=telescope with x diameter

H. Kamerlingh-Ohnes

a.k.a max planck’s uncle willy