- barometer
- barometric pressure
- barometry
- barotropic phenomenon
- barrel distortion
- barrel plating
- baryon decay
- baryon octet
- base
- basic
- basic access
- batch freezing
- batch mixer
- bathysphere
- battery clip
- Baume density
- bayonet cap
- bayonet coupling
- bead thermistor
- beam angle
- battery
- bead
- beam
- beam axis
- beam blanking
- beam splitter
- bearing liner
- beat frequency
- Becquerel effect
- beer cooling
- bellows valve
- belted cable
- bend test
- bending
- bending breaking
- Bessel function
- beta decay
- beta detection
- beta radiation
- beta radioactivity
- beta ray
- beta-disintegration
- beta-peak
- beta-spectroscopy
- beta-spectrum
- Bethe region
- bevel
- beverage container
- BH-product
- bias
- bias distortion
- bias error
- bias light
- biasing
- biaxial crystal
- biconcave lens
- biconical
- biconvex lens
- bidirectional bus
- bidirectional fan
- bidirectional graph
- bifilar
- bifilar circuit
- bifilar resistor
- bifilar suspension
- bifilar transformer
- bifilar winding
- bifocal
- bifocal lens
- bifurcated contact
- bifurcating box
- Big bang
- bilateral
- bilateral circuit
- bilateral network
- binary
- biharmonic
- billion
- binary control
- binary system
- binocular
- binocular camera
- bioacoustics
- biochemistry
- bioelectronics
- biological transducers
- bioluminescence
- biomagnetism
- biophysics
- bipartition
- biperiodic
- biplate
- bipolar
- bipolar code
- bipolar machine
- bipolar transistor
- bipolarity
- biquinary
- birdies
- birefringence