P3.1 - New Technology Flashcards
What is an analogue signal?
A signal that can have any value
e.g. transverse wave
What is a digital signal?
A signal that can only have the two values 1 or 0 (binary)
e.g. longitudinal wave
How are bits (1 or 0) stored on a magnetic storage drive?
Small magnetic bits of material show how they are magnetised
e.g. S-N = 1, N-S = 0
What is the calculation for efficiency?
efficiency (%) = ( useful energy / total energy ) * 100
What does LED stand for?
Light-Emitting Diode
What does LDR stand for?
Light dependent resistor
What are the 2 type of waves on the electromagnetic spectrum that technology usually communicates through?
microwaves and radiowaves
What is the efficiency of LEDs?
around 30%
How does the resistance of a LDR change based on light levels?
A higher light level means the resistance decreases
How can LDR’s improve efficiency?
They can be used to detect daylight to turn off lights when they are not in use.
What is a use of a thermistor?
They are used in incubators to control temperatures
How does a thermistor work?
The resistance changes with the surrounding temperature
What is a device that is used to check someone’s oxygen saturation (%SpO2) in their blood?
Oximeter
What is total internal reflection?
Where light reflects fully off the boundary of 2 media
What are the two conditions required for total internal reflection?
- light to be traveling from a more dense medium to a less dense medium
- the angle of incidence must be greater than the critical angle
What is the critical angle of a medium?
At a certian angle of incidence, light will refract 90° and travel along the boundary of the two media
What is an endoscope?
A piece of equipment used to view someones insides using optical fibres and a camera.
How does an x-ray work?
X-rays are sent through the body and then hit a detector. Bones are more dense than tissue so they absorb x-rays and leave an image of what x-rays came through the body.
What are gamma rays used for?
To observing how someones kidneys are functioning
What are x-rays used for?
- Observing bones and if they are damages
- Spotting tumors
What are ultrasounds used for?
Viewing organs and their content
What does MRI stand for?
Magnetic Resonance Imaging
What are MRIs used for?
producing a detailed image of an organ works
What would you need to find out if you want to know where an object will go when hit?
- angle when hit
- initial speed
What is reaction time?
the amount of time taken for a person to respond to a stimulus or event
What is the average human reaction time?
0.2 seconds
200 milliseconds
What happens in nuclear fission?
Atoms are split apart creating energy
What happens in nuclear fusion?
Atoms are fused/joined together which creates energy. Usually hydrogen atoms are fused into helium.
Do solar cells use a generator?
No, they absorb light and create P.D. directly
P.D. - Potential Difference
What is an incubator
A safe controlled environment
What is the amplitude of a wave
height from the peak to the centre of a wave
What is the frequency of a wave
how many waves pass a fixed point over an amount of time
