--- /srv/reproducible-results/rbuild-debian/r-b-build.H9juKJRu/b1/eyes17-manuals_5.3.1+repack-1_amd64.changes +++ /srv/reproducible-results/rbuild-debian/r-b-build.H9juKJRu/b2/eyes17-manuals_5.3.1+repack-1_amd64.changes ├── Files │ @@ -1,5 +1,5 @@ │ │ - 4266a27b854eaca1b490f6388d0e5ae4 4798980 science optional eyes17-manuals-en_5.3.1+repack-1_all.deb │ + 025527ee920dbf630e35c6bc89fc6dbe 4790700 science optional eyes17-manuals-en_5.3.1+repack-1_all.deb │ 5a4f34907fdf5dae7fc6c707238afc8c 1986508 science optional eyes17-manuals-es_5.3.1+repack-1_all.deb │ 294b36eb7d80de9759f6f6d68ae68076 4886804 science optional eyes17-manuals-fr_5.3.1+repack-1_all.deb │ 85de996c74f7bc066628ae2cc0cb7d4a 4309352 science optional eyes17-manuals-ml_5.3.1+repack-1_all.deb ├── eyes17-manuals-en_5.3.1+repack-1_all.deb │ ├── file list │ │ @@ -1,3 +1,3 @@ │ │ -rw-r--r-- 0 0 0 4 2023-11-05 11:10:27.000000 debian-binary │ │ -rw-r--r-- 0 0 0 1072 2023-11-05 11:10:27.000000 control.tar.xz │ │ --rw-r--r-- 0 0 0 4797716 2023-11-05 11:10:27.000000 data.tar.xz │ │ +-rw-r--r-- 0 0 0 4789436 2023-11-05 11:10:27.000000 data.tar.xz │ ├── control.tar.xz │ │ ├── control.tar │ │ │ ├── ./control │ │ │ │ @@ -1,13 +1,13 @@ │ │ │ │ Package: eyes17-manuals-en │ │ │ │ Source: eyes17-manuals │ │ │ │ Version: 5.3.1+repack-1 │ │ │ │ Architecture: all │ │ │ │ Maintainer: Georges Khaznadar │ │ │ │ -Installed-Size: 4736 │ │ │ │ +Installed-Size: 4728 │ │ │ │ Recommends: calibre, evince │ │ │ │ Conflicts: eyes17 (<< 5.1) │ │ │ │ Provides: eyes17-manuals │ │ │ │ Section: science │ │ │ │ Priority: optional │ │ │ │ Homepage: http://expeyes.in/ │ │ │ │ Description: Eyes17 User Manuals (English version) │ │ │ ├── ./md5sums │ │ │ │ ├── ./md5sums │ │ │ │ │┄ Files differ │ ├── data.tar.xz │ │ ├── data.tar │ │ │ ├── file list │ │ │ │ @@ -1,14 +1,14 @@ │ │ │ │ drwxr-xr-x 0 root (0) root (0) 0 2023-11-05 11:10:27.000000 ./ │ │ │ │ drwxr-xr-x 0 root (0) root (0) 0 2023-11-05 11:10:27.000000 ./usr/ │ │ │ │ drwxr-xr-x 0 root (0) root (0) 0 2023-11-05 11:10:27.000000 ./usr/share/ │ │ │ │ drwxr-xr-x 0 root (0) root (0) 0 2023-11-05 11:10:27.000000 ./usr/share/doc/ │ │ │ │ drwxr-xr-x 0 root (0) root (0) 0 2023-11-05 11:10:27.000000 ./usr/share/doc/eyes17/ │ │ │ │ drwxr-xr-x 0 root (0) root (0) 0 2023-11-05 11:10:27.000000 ./usr/share/doc/eyes17/en/ │ │ │ │ -rw-r--r-- 0 root (0) root (0) 1955609 2023-11-05 11:10:27.000000 ./usr/share/doc/eyes17/en/eyes17.epub │ │ │ │ --rw-r--r-- 0 root (0) root (0) 2877621 2023-11-05 11:10:27.000000 ./usr/share/doc/eyes17/en/eyes17.pdf.gz │ │ │ │ +-rw-r--r-- 0 root (0) root (0) 2869454 2023-11-05 11:10:27.000000 ./usr/share/doc/eyes17/en/eyes17.pdf.gz │ │ │ │ drwxr-xr-x 0 root (0) root (0) 0 2023-11-05 11:10:27.000000 ./usr/share/doc/eyes17-manuals-en/ │ │ │ │ -rw-r--r-- 0 root (0) root (0) 492 2023-11-05 11:10:27.000000 ./usr/share/doc/eyes17-manuals-en/changelog.Debian.gz │ │ │ │ -rw-r--r-- 0 root (0) root (0) 3036 2023-11-05 11:09:03.000000 ./usr/share/doc/eyes17-manuals-en/copyright │ │ │ │ drwxr-xr-x 0 root (0) root (0) 0 2023-11-05 11:10:27.000000 ./usr/share/eyes17/ │ │ │ │ drwxr-xr-x 0 root (0) root (0) 0 2023-11-05 11:10:27.000000 ./usr/share/eyes17/doc/ │ │ │ │ lrwxrwxrwx 0 root (0) root (0) 0 2023-11-05 11:10:27.000000 ./usr/share/eyes17/doc/en -> ../../doc/eyes17/en │ │ │ ├── ./usr/share/doc/eyes17/en/eyes17.pdf.gz │ │ │ │ ├── eyes17.pdf │ │ │ │ │ ├── pdftotext {} - │ │ │ │ │ │ @@ -81,23 +81,23 @@ │ │ │ │ │ │ 12 │ │ │ │ │ │ 13 │ │ │ │ │ │ 13 │ │ │ │ │ │ 15 │ │ │ │ │ │ 16 │ │ │ │ │ │ 17 │ │ │ │ │ │ 18 │ │ │ │ │ │ +19 │ │ │ │ │ │ 20 │ │ │ │ │ │ 21 │ │ │ │ │ │ -21 │ │ │ │ │ │ 22 │ │ │ │ │ │ 23 │ │ │ │ │ │ +24 │ │ │ │ │ │ +25 │ │ │ │ │ │ 25 │ │ │ │ │ │ 26 │ │ │ │ │ │ -26 │ │ │ │ │ │ -27 │ │ │ │ │ │ │ │ │ │ │ │ 3 Electronics │ │ │ │ │ │ 3.1 Oscilloscope and other Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . │ │ │ │ │ │ 3.2 Half wave rectifier using PN junction . . . . . . . . . . . . . . . . . . . . . . . . . . . │ │ │ │ │ │ 3.3 Fullwave rectifier using PN junctions . . . . . . . . . . . . . . . . . . . . . . . . . . . │ │ │ │ │ │ 3.4 Clipping using PN junction diode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . │ │ │ │ │ │ 3.5 Clamping using PN junction diode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . │ │ │ │ │ │ @@ -889,23 +889,23 @@ │ │ │ │ │ │ Socket │ │ │ │ │ │ │ │ │ │ │ │ 2.10.2 Procedure │ │ │ │ │ │ • Connect a long wire to A1 │ │ │ │ │ │ • Take one end of the wire near the AC mains line, without touching any mains supply. │ │ │ │ │ │ • Enable A1, and it’s analysis. │ │ │ │ │ │ │ │ │ │ │ │ +The amplitude of the pickup depends on the wattage of the electrical equipment operating nearby, distance │ │ │ │ │ │ +to them and on the length of the wire used. │ │ │ │ │ │ + │ │ │ │ │ │ 16 │ │ │ │ │ │ │ │ │ │ │ │ Chapter 2. School Level Experiments │ │ │ │ │ │ │ │ │ │ │ │ expEYES-17 Documentation, Release 4.7 │ │ │ │ │ │ │ │ │ │ │ │ -The amplitude of the pickup depends on the wattage of the electrical equipment operating nearby, distance │ │ │ │ │ │ -to them and on the length of the wire used. │ │ │ │ │ │ - │ │ │ │ │ │ 2.11 Separating DC & AC components │ │ │ │ │ │ A capacitor does not allow DC to pass through it. This property can be demonstrated using a squarewave │ │ │ │ │ │ swinging from 0 to 5V. │ │ │ │ │ │ │ │ │ │ │ │ SQ1 │ │ │ │ │ │ │ │ │ │ │ │ A1 │ │ │ │ │ │ @@ -942,20 +942,14 @@ │ │ │ │ │ │ It is well known that touching the mains supply is fatal. This is because our body conducts electricity. │ │ │ │ │ │ At the same time you cannot light an LED from a drycell by using your fingers to make the connection. │ │ │ │ │ │ We can explore this further using the low voltage AC and DC sources of ExpEYES. │ │ │ │ │ │ │ │ │ │ │ │ 2.12.1 Objective │ │ │ │ │ │ To study the electrical conduction of human body │ │ │ │ │ │ │ │ │ │ │ │ -18 │ │ │ │ │ │ - │ │ │ │ │ │ -Chapter 2. School Level Experiments │ │ │ │ │ │ - │ │ │ │ │ │ - expEYES-17 Documentation, Release 4.7 │ │ │ │ │ │ - │ │ │ │ │ │ 2.12.2 Procedure │ │ │ │ │ │ │ │ │ │ │ │ A1 │ │ │ │ │ │ │ │ │ │ │ │ A2 │ │ │ │ │ │ │ │ │ │ │ │ WG │ │ │ │ │ │ @@ -965,17 +959,17 @@ │ │ │ │ │ │ • Connect one end of another wire to A2 │ │ │ │ │ │ • Enable A1, A2 and their amplitude and frequency display. │ │ │ │ │ │ • Hold the unconnected ends of both wires by your hands. │ │ │ │ │ │ • Repeat it using a 3 volt DC signal from PV1. │ │ │ │ │ │ The observed voltage waveforms are shown below. The voltage on A2 is slightly less than 3volts, due to │ │ │ │ │ │ the resistance of the body. │ │ │ │ │ │ │ │ │ │ │ │ -2.12. Human body as a conductor │ │ │ │ │ │ +18 │ │ │ │ │ │ │ │ │ │ │ │ -19 │ │ │ │ │ │ +Chapter 2. School Level Experiments │ │ │ │ │ │ │ │ │ │ │ │ expEYES-17 Documentation, Release 4.7 │ │ │ │ │ │ │ │ │ │ │ │ 2.12.3 Discussion │ │ │ │ │ │ Using DC the voltage reaching A2 is smaller, which means that body conducts AC better than DC. │ │ │ │ │ │ The voltage measured at A2 is decided by the ratio of the resistance offered by the body and the input impedance (1M Ω) of A2. The phase difference between the two waves implies that there is some │ │ │ │ │ │ capacitance present in the circuit. │ │ │ │ │ │ @@ -1000,31 +994,31 @@ │ │ │ │ │ │ PV1 │ │ │ │ │ │ │ │ │ │ │ │ GND │ │ │ │ │ │ │ │ │ │ │ │ 100K │ │ │ │ │ │ │ │ │ │ │ │ hand hand │ │ │ │ │ │ +2.13. Resistance of human body │ │ │ │ │ │ + │ │ │ │ │ │ +19 │ │ │ │ │ │ + │ │ │ │ │ │ + expEYES-17 Documentation, Release 4.7 │ │ │ │ │ │ + │ │ │ │ │ │ 2.13.2 Procedure │ │ │ │ │ │ • Set PV1 to 3 volts │ │ │ │ │ │ • Connect a wire from PV1 to A1 │ │ │ │ │ │ • Connect one end of a wire to PV1 │ │ │ │ │ │ • Connect one end of another wire to A2 │ │ │ │ │ │ • Connect a 100Ω resistor from A2 to ground. │ │ │ │ │ │ • Enable the Checkboxes to display A1 and A2 │ │ │ │ │ │ • Hold the unconnected ends of both wires by your hands. │ │ │ │ │ │ • Repeat using SINE instead of PV1. │ │ │ │ │ │ • Enable amplitude and frequency display for A1 and A2. │ │ │ │ │ │ │ │ │ │ │ │ -20 │ │ │ │ │ │ - │ │ │ │ │ │ -Chapter 2. School Level Experiments │ │ │ │ │ │ - │ │ │ │ │ │ - expEYES-17 Documentation, Release 4.7 │ │ │ │ │ │ - │ │ │ │ │ │ 2.13.3 Discussion │ │ │ │ │ │ The AC resistance is less than the DC resistance. The resistance is due to our skin and AC can pass │ │ │ │ │ │ through this, like it passes through the dielectric material of a capacitor. A bit of exploring will reveal │ │ │ │ │ │ that a capacitor is formed between the tip of the wire and blood inside with the skin acting as a dielectric. │ │ │ │ │ │ Explore the effect of a metal plate at the tip of the wire. │ │ │ │ │ │ │ │ │ │ │ │ 2.14 Light dependent resistors │ │ │ │ │ │ @@ -1048,32 +1042,32 @@ │ │ │ │ │ │ • Connect the LDR from SEN to ground │ │ │ │ │ │ • Connect a wire from SEN to A1 │ │ │ │ │ │ • Measure the LDR’s resistance, for different light intensities. │ │ │ │ │ │ • Iluminate LDR using a fluorescent lamp, A1 should show ripples │ │ │ │ │ │ • Set the time base to 200mS full scale │ │ │ │ │ │ • Put A1 in AC mode, using the switch, and measure ripple frequency │ │ │ │ │ │ │ │ │ │ │ │ +20 │ │ │ │ │ │ + │ │ │ │ │ │ +Chapter 2. School Level Experiments │ │ │ │ │ │ + │ │ │ │ │ │ + expEYES-17 Documentation, Release 4.7 │ │ │ │ │ │ + │ │ │ │ │ │ 2.14.3 Discussion │ │ │ │ │ │ The resistance vary from 1kΩ to around 100 kΩ depending on the intensity of light falling on it. The │ │ │ │ │ │ voltage is proportional to the resistance. The resistance decreases with intensity of light. If you use a │ │ │ │ │ │ point source of light, the resistance should increase as the square of the distance between the LDR and │ │ │ │ │ │ the light source. The light from a fluorescent lamp operating at 50Hz has 100Hz ripples and these can │ │ │ │ │ │ be measured. │ │ │ │ │ │ │ │ │ │ │ │ 2.15 Voltage of a lemon cell │ │ │ │ │ │ A lemon cell is formed by inserting Copper and Zinc plates in to a lemon, or any dilute acid. The voltage │ │ │ │ │ │ developed across the electrodes is very small and the cell has a very high internal resistance. Due to this │ │ │ │ │ │ the voltage drops when a load resistor is connected. │ │ │ │ │ │ │ │ │ │ │ │ -2.14. Light dependent resistors │ │ │ │ │ │ - │ │ │ │ │ │ -21 │ │ │ │ │ │ - │ │ │ │ │ │ - expEYES-17 Documentation, Release 4.7 │ │ │ │ │ │ - │ │ │ │ │ │ 2.15.1 Objective │ │ │ │ │ │ Make a lemon cell and explore it’s internal resistance. │ │ │ │ │ │ │ │ │ │ │ │ GND │ │ │ │ │ │ │ │ │ │ │ │ 1K │ │ │ │ │ │ Zn │ │ │ │ │ │ @@ -1095,39 +1089,37 @@ │ │ │ │ │ │ volts. When connected, current will start flowing through the resistor. But why is the voltage going down │ │ │ │ │ │ ? │ │ │ │ │ │ What is the internal resistance of the cell ? │ │ │ │ │ │ Current is the flow of charges and it has to complete the path. That means, current has to flow through │ │ │ │ │ │ the cell also. Depending on the internal resistance of the cell, part of the voltage gets dropped inside the │ │ │ │ │ │ cell itself. Does the same happen with a new dry-cell ? │ │ │ │ │ │ │ │ │ │ │ │ +2.15. Voltage of a lemon cell │ │ │ │ │ │ + │ │ │ │ │ │ +21 │ │ │ │ │ │ + │ │ │ │ │ │ + expEYES-17 Documentation, Release 4.7 │ │ │ │ │ │ + │ │ │ │ │ │ 2.16 A simple AC generator │ │ │ │ │ │ A voltage will be induced across a conductor placed in a changing magnetic field. This can be demonstrated by making a simple AC generator. Use the 10 mm x 10 mm magnet and the 3000T coils that │ │ │ │ │ │ comes with the kit. │ │ │ │ │ │ │ │ │ │ │ │ 2.16.1 Objective │ │ │ │ │ │ Measure the frequency and amplitude of the voltage induced across a solenoid coil kept near a rotating │ │ │ │ │ │ magnet. Use more than one coils to generate multi-phase AC. │ │ │ │ │ │ - │ │ │ │ │ │ -22 │ │ │ │ │ │ - │ │ │ │ │ │ -Chapter 2. School Level Experiments │ │ │ │ │ │ - │ │ │ │ │ │ - expEYES-17 Documentation, Release 4.7 │ │ │ │ │ │ - │ │ │ │ │ │ Rotating │ │ │ │ │ │ Magnet │ │ │ │ │ │ │ │ │ │ │ │ A2 │ │ │ │ │ │ GND │ │ │ │ │ │ - │ │ │ │ │ │ -Coil │ │ │ │ │ │ - │ │ │ │ │ │ 1.5V │ │ │ │ │ │ CELL │ │ │ │ │ │ │ │ │ │ │ │ +Coil │ │ │ │ │ │ + │ │ │ │ │ │ A1 │ │ │ │ │ │ Coil │ │ │ │ │ │ │ │ │ │ │ │ DC │ │ │ │ │ │ MOTOR │ │ │ │ │ │ │ │ │ │ │ │ GND │ │ │ │ │ │ @@ -1143,29 +1135,29 @@ │ │ │ │ │ │ The voltage output is shown in figure. The phase difference between the two voltages depends on the │ │ │ │ │ │ angle between the axes of the two coils. │ │ │ │ │ │ Bring a shorted coil near the magnet to observe the change in frequency. The shorted coil is drawing │ │ │ │ │ │ energy from the generator and the speed get reduced. The magnetic field in this generator is very weak. │ │ │ │ │ │ The resistance of the coil is very high and trying to draw any current from it will drop most of the voltage │ │ │ │ │ │ across the coil itself. │ │ │ │ │ │ │ │ │ │ │ │ +22 │ │ │ │ │ │ + │ │ │ │ │ │ +Chapter 2. School Level Experiments │ │ │ │ │ │ + │ │ │ │ │ │ + expEYES-17 Documentation, Release 4.7 │ │ │ │ │ │ + │ │ │ │ │ │ 2.17 AC Transformer │ │ │ │ │ │ There will be a time varying magnetic field around a conductor carrying AC. A voltage will be induced │ │ │ │ │ │ across another conductor placed in this field. This is the working principle of a transformer, that can be │ │ │ │ │ │ demonstrated using the two coils included in the kit. │ │ │ │ │ │ │ │ │ │ │ │ 2.17.1 Objective │ │ │ │ │ │ Construct a transformer demonstrate mutual induction using two coils. One coil, the primary, is connected between WG and Ground. The axes of the coils are aligned and any ferromagnetic material may │ │ │ │ │ │ be inserted for better coupling. │ │ │ │ │ │ │ │ │ │ │ │ -2.17. AC Transformer │ │ │ │ │ │ - │ │ │ │ │ │ -23 │ │ │ │ │ │ - │ │ │ │ │ │ - expEYES-17 Documentation, Release 4.7 │ │ │ │ │ │ - │ │ │ │ │ │ 2.17.2 Procedure │ │ │ │ │ │ │ │ │ │ │ │ WG │ │ │ │ │ │ │ │ │ │ │ │ A1 │ │ │ │ │ │ │ │ │ │ │ │ COIL1 │ │ │ │ │ │ @@ -1178,28 +1170,28 @@ │ │ │ │ │ │ │ │ │ │ │ │ • Make connections as shown in the figure │ │ │ │ │ │ • Enable A1 and A2 │ │ │ │ │ │ • Set WG to 1000 Hz │ │ │ │ │ │ • Bring the coils close and watch the voltage on A2. │ │ │ │ │ │ • Try inserting an iron core, a nail or screwdriver also would do. │ │ │ │ │ │ │ │ │ │ │ │ +2.17. AC Transformer │ │ │ │ │ │ + │ │ │ │ │ │ +23 │ │ │ │ │ │ + │ │ │ │ │ │ + expEYES-17 Documentation, Release 4.7 │ │ │ │ │ │ + │ │ │ │ │ │ 2.17.3 Discussion │ │ │ │ │ │ The applied waveform and the induced waveform are shown in figure. A changing magnetic filed is │ │ │ │ │ │ causing the induced voltage. In the previous two experiments, the changing magnetic field was created │ │ │ │ │ │ by the movement of permanent magnets. In the present case the changing magnetic field is created by a │ │ │ │ │ │ time varying current. │ │ │ │ │ │ Try doing this experiment using a squarewave. Connect a 1kΩ resistor across secondary coil to reduce │ │ │ │ │ │ ringing. │ │ │ │ │ │ │ │ │ │ │ │ -24 │ │ │ │ │ │ - │ │ │ │ │ │ -Chapter 2. School Level Experiments │ │ │ │ │ │ - │ │ │ │ │ │ - expEYES-17 Documentation, Release 4.7 │ │ │ │ │ │ - │ │ │ │ │ │ 2.18 Resistance of water, using AC │ │ │ │ │ │ Resistance of water is an indication of it’s purity. Water conducts mostly due to the dissolved salts. If │ │ │ │ │ │ you have never tried measuring the resistance of ordinary tap water try doing it with a multimeter. Are │ │ │ │ │ │ you getting a stable reading ? │ │ │ │ │ │ │ │ │ │ │ │ 2.18.1 Objective │ │ │ │ │ │ Measure the resistance of ionic solutions, using AC voltages, using normal tap water. │ │ │ │ │ │ @@ -1227,29 +1219,28 @@ │ │ │ │ │ │ A2 │ │ │ │ │ │ Resistance offered by water Rw = VA1 −V │ │ │ │ │ │ = VA1V−V │ │ │ │ │ │ × R1 . │ │ │ │ │ │ I │ │ │ │ │ │ A2 │ │ │ │ │ │ │ │ │ │ │ │ +24 │ │ │ │ │ │ + │ │ │ │ │ │ +Chapter 2. School Level Experiments │ │ │ │ │ │ + │ │ │ │ │ │ + expEYES-17 Documentation, Release 4.7 │ │ │ │ │ │ + │ │ │ │ │ │ 2.18.3 Discussion │ │ │ │ │ │ The experiment may be repeated using DC from PV1. Use the DC displays of A1 and A2 while using │ │ │ │ │ │ DC. With DC, the resistance of the liquid changes with time, but AC gives a steady reading. When done │ │ │ │ │ │ using water in a cup with two wire ends dippped in it, the resistance does not depend much on the distance │ │ │ │ │ │ between the electrodes, the area of the electrode is having some effect. To find out the resistivity of water │ │ │ │ │ │ we need to use a column of water in a tube, with electrode plates at both ends. │ │ │ │ │ │ The resistance depends on the ion concentration and presence of impurities in the water used. Try adding │ │ │ │ │ │ some common salt and repeat the measurements. │ │ │ │ │ │ - │ │ │ │ │ │ -2.18. Resistance of water, using AC │ │ │ │ │ │ - │ │ │ │ │ │ -25 │ │ │ │ │ │ - │ │ │ │ │ │ - expEYES-17 Documentation, Release 4.7 │ │ │ │ │ │ - │ │ │ │ │ │ Why is the behavior different for AC and DC ? What are the charge carriers responsible for the flow of │ │ │ │ │ │ electricity through solutions ? Is there any chemical reaction taking place ? │ │ │ │ │ │ │ │ │ │ │ │ 2.19 Generating sound │ │ │ │ │ │ Electrical signals can be converted into sound using devices like loudspeaker, Piezo buzzer etc. We use │ │ │ │ │ │ a buzzer because available loudspeakers have a low impedance and require more current. │ │ │ │ │ │ │ │ │ │ │ │ @@ -1273,24 +1264,24 @@ │ │ │ │ │ │ of the Piezo buzzer is decided by its size and the mechanical properties. │ │ │ │ │ │ │ │ │ │ │ │ 2.20 Digtizing sound │ │ │ │ │ │ Sound waves create pressure variations in the medium through which it travel. The microphone generates │ │ │ │ │ │ a voltage proportional to the pressure change. You can consider the microphone as a pressure sensor, but │ │ │ │ │ │ working only for time varying pressures. │ │ │ │ │ │ │ │ │ │ │ │ -2.20.1 Objective │ │ │ │ │ │ -Digitize sound signals from a microphone, and measure its frequency. Use the Piezo buzzer or any other │ │ │ │ │ │ -source of sound like a tuning fork. │ │ │ │ │ │ - │ │ │ │ │ │ -26 │ │ │ │ │ │ +2.19. Generating sound │ │ │ │ │ │ │ │ │ │ │ │ -Chapter 2. School Level Experiments │ │ │ │ │ │ +25 │ │ │ │ │ │ │ │ │ │ │ │ expEYES-17 Documentation, Release 4.7 │ │ │ │ │ │ │ │ │ │ │ │ +2.20.1 Objective │ │ │ │ │ │ +Digitize sound signals from a microphone, and measure its frequency. Use the Piezo buzzer or any other │ │ │ │ │ │ +source of sound like a tuning fork. │ │ │ │ │ │ + │ │ │ │ │ │ 2.20.2 Procedure │ │ │ │ │ │ │ │ │ │ │ │ MIC │ │ │ │ │ │ │ │ │ │ │ │ GND │ │ │ │ │ │ │ │ │ │ │ │ Source of Sound │ │ │ │ │ │ @@ -1310,18 +1301,17 @@ │ │ │ │ │ │ │ │ │ │ │ │ 2.21 Stroboscope │ │ │ │ │ │ A stroboscope is an instrument used to make a cyclically moving object appear to be slow-moving, or │ │ │ │ │ │ stationary. It consists of light source which produces brief repetitive flashes of light. If a body rotating at │ │ │ │ │ │ some frequency is illuminated with a light flashing at the same frequency, it is visible only when it is at │ │ │ │ │ │ a particular position. This gives an impression that it is stationary. If the two frequencies differ slightly, │ │ │ │ │ │ the body will apprear to move very slowly. │ │ │ │ │ │ +26 │ │ │ │ │ │ │ │ │ │ │ │ -2.21. Stroboscope │ │ │ │ │ │ - │ │ │ │ │ │ -27 │ │ │ │ │ │ +Chapter 2. School Level Experiments │ │ │ │ │ │ │ │ │ │ │ │ expEYES-17 Documentation, Release 4.7 │ │ │ │ │ │ │ │ │ │ │ │ 2.21.1 Objective │ │ │ │ │ │ Observation of a rotating body with a periodic flashed light, using a disk with a marker. │ │ │ │ │ │ │ │ │ │ │ │ LED │ │ │ │ │ │ @@ -1344,14 +1334,20 @@ │ │ │ │ │ │ 2.21.3 Discussion │ │ │ │ │ │ When the frequency of the phenomenon under observation and the frequency of the flashing light are │ │ │ │ │ │ matching, one can see a still image. │ │ │ │ │ │ What happens when the frequency of the light is slightly increased, or slightly decreased? │ │ │ │ │ │ What happens when the frequency of the flashing light is twice the frequency of the phenomenon? and │ │ │ │ │ │ when it is the half of its value? │ │ │ │ │ │ │ │ │ │ │ │ +2.21. Stroboscope │ │ │ │ │ │ + │ │ │ │ │ │ +27 │ │ │ │ │ │ + │ │ │ │ │ │ + expEYES-17 Documentation, Release 4.7 │ │ │ │ │ │ + │ │ │ │ │ │ 28 │ │ │ │ │ │ │ │ │ │ │ │ Chapter 2. School Level Experiments │ │ │ │ │ │ │ │ │ │ │ │ CHAPTER │ │ │ │ │ │ │ │ │ │ │ │ THREE