IB Physics Glossary
Browse the glossary using this index
Special | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | ALL
B |
|---|
Bacquerel , Bq, is the SI unit of activity for radioactive sources. It is equivalent to a count or disintegration per second. The activity is measured, typically, with a Geiger-Muller (GM) tube. | |
Beta decay $$^A_ZX \rightarrow~{}^{A}_{Z+1}Y + ^{0}_{-1}\beta + ^{0}_{0}\bar{\nu}$$ or $$^A_ZX \rightarrow~{}^{A}_{Z+1}Y + ^{0}_{-1}e + ^{0}_{0}\bar{\nu}$$. Where X is the parent nucleus, Y is the daughter nucleus, A is the number of nucleons and Z is the number of protons. An example decay is $$^{90}_{38}Sr \rightarrow~{}^{90}_{39}Y + ^{0}_{-1}\beta + ^{0}_{0}\bar{\nu}$$. Properties of beta particles include
| |
Binary to decimal conversionfor a five bit-number $$b_4 b_3 b_2 b_1 b_0$$ the decimal equivalent is $$b_4 \times 2^4 + b_3 \times 2^3 + b_2 \times 2^2 + b_1 \times 2^1 + b_0 \times 2^0$$. An example is the binary number $$10101$$ which in decimal is $$1 \times 2^4 + 0 \times 2^3 + 1 \times 2^2 + 0 \times 2^1 + 1 \times 2^0 = 21$$. | |
Binding energy is the energy required to assemble a nucleus or to separate the nucleus into its individual components/nucleons. (d) The binding energy per nucleon is the total binding energy for a particular nucleus divided by the number of nucleons contained in the nucleus. For energy to be released in a nuclear reaction, fusion or fission, the binding energy must increase.  Image taken from http://www.smsec.com/en/nucl/07_1.htm | |
Blind spot is a region where the optical nerve leaves the retina which does not contain rods or cones. | |
Brewster's law When the angle of incidence equals Brewster's angle, the reflected and the refracted rays are perpendicular to each other. The reflected ray becomes completely horizontally plane-polarized.
$$n=\tan \phi$$ | |
C |
|---|
Capacitanceis the ratio of charge to potential difference or voltage, $$C=\frac{Q}{V}$$. Its units are Farads. | |
CCDis a charged coupled device such that the amount of charge that builds up on one of its pixels is proportional to the light intensity falling on the pixel.
The photoelectric effect is responsible for conversion of photons energy to electron energy. | |
CCD resolutionis possible if the size of an image covers at least two pixels. | |
CD/DVD pit depthis given by $$d = \frac{\lambda}{4}$$where $$\lambda$$ is the wavelength of the laser for the CD/DVD reader.The distance corresponds to a total additional distance of $$\frac{\lambda}{2}$$ travelled by the laser light at a pit-land interface (corresponding to binary 1). DVDs (shorter pit length and double layers) have about 7 times the storage capacity of CDs. Changing or reducing the laser wavelength can increase the resolution, by decreasing $$\theta= 1.22 \frac{\lambda}{b}$$, thus allowing more pits and therefore greater storage capacity. Bluray technology uses shorter wavelength laser light. | |