What is Electroscope: Definition and 36 Discussions

The electroscope is an early scientific instrument used to detect the presence of electric charge on a body. It detects charge by the movement of a test object due to the Coulomb electrostatic force on it. The amount of charge on an object is proportional to its voltage. The accumulation of enough charge to detect with an electroscope requires hundreds or thousands of volts, so electroscopes are used with high voltage sources such as static electricity and electrostatic machines. An electroscope can only give a rough indication of the quantity of charge; an instrument that measures electric charge quantitatively is called an electrometer.
The electroscope was the first electrical measuring instrument. The first electroscope was a pivoted needle (called the versorium), invented by British physician William Gilbert around 1600. The pith-ball electroscope and the gold-leaf electroscope are two classical types of electroscope that are still used in physics education to demonstrate the principles of electrostatics. A type of electroscope is also used in the quartz fiber radiation dosimeter. Electroscopes were used by the Austrian scientist Victor Hess in the discovery of cosmic rays.

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  1. sarah123

    Describe how you could use a pith ball as an electroscope

    Would it still work in a similar manner as an actual electroscope where you would charge it either positively or negatively and then observe attractive or repulsive forces or is there an easier and more efficient method?
  2. V

    How does the electroscope lose electrons to the Earth?

    I get step 1, in which due to electrostatic induction the top part of electroscope gets positively charged while the leaves of electroscope become negatively charged. Now if we Earth the positively charged end of electroscope as shown in step 2, then electrons must flow from Earth to...
  3. T

    Electrical Calibrating a metal leaf or pith ball electroscope

    I'm trying to build a DIY metal leaf or pith ball electroscope. I want to provide it with a circular arc voltage scale visible directly behind the (deflected) ends of the leaves. To calibrate the scale with ballpark accuracy, I want to determine the charge density upon the leaf pair (or pith...
  4. MatinSAR

    Experiment with an Electroscope, a Charged Rod and my hand

    I know that if we bring a positively charged rod closer to the electroscope, charges of electroscope are separated and the leaves of the electroscope get away from each other. but what happens if we touch the positively charged rod with our hands and then move the hand and rod away?
  5. Muhammad Danish

    Detecting Alpha Radiation

    Can we use Gold Leaf Electroscope to check whether a radioactive material gives off Alpha particles?
  6. J

    How do the electroscope leaves behave after grounding?

    Homework Statement A positively charged rod is brought near the knob of an uncharged electroscope and the leaves of the electroscope diverge. As the positively charged rod is held near the knob, the electroscope is grounded with a wire. Then the grounding wire and the positively charged rod...
  7. D

    Electroscope experiment in vacuum

    Hi I am running the electroscope experiment in vacuum. This is shown in (a) in the uploaded figure . Once the aluminum leafs are charged the chamber is pump down (b). As soon the pressure decrease low enough (around relative pressure of 30 inHg) the leafs collapse to each other abruptly. Here...
  8. TheQuietOne

    Homemade electroscope help

    I want to make a electroscope but tried googling it and none made my criteria. What I want is a homemade electroscope that will give me a measurement, please tell what I would need and possibly a how to. Thank you
  9. David Anton

    Measuring charge (or potential) with electroscope?

    I am trying to measure the charge(or voltage) of a positively charged sphere by touching it with a non- calibrated electroscope. I am getting consistent results in the separation(or angle) between the metal leaves, but I don´t know how to calculate the voltage between the leaves from there. I...
  10. T

    Electric Charge Applied on Two Wires of Electroscope?

    Homework Statement A large electroscope is made with "leaves" that are 78-cm-long wires with tiny 24-g spheres at the ends. When charged, nearly all the charge resides on the ends of the spheres. (See diagram attached) If the wires each make a 26° angle with the vertical, what total charge Q...
  11. gracy

    Gold leaf electroscope problem

    Homework Statement http://www.physicstutorials.org/home/electrostatics/electroscope Negatively charged electroscope and X-Y plates are placed like in the figure given below. If the distances between electroscope and conductor plates are equals; find the types of charges of plates for given...
  12. gracy

    Current in metal rod of gold leaf electroscope -- is it there?

    In gold leaf electroscope from the following video I have a doubt From time 2:11 to 2:14 flow of negative charge i.e flow of electron won't it cause current?
  13. L

    Position of unknown material on electrostatic series?

    Homework Statement You have a new unknown material. You want to get a rough approximation as to the location of the unknown material on the electrostatic series. You only have two tools at your disposal; some wax and a charge detector. Design an experiment (procedure) that will help you...
  14. N

    Determine the total charge needed to apply to the electroscope.

    Homework Statement A large electroscope is made with "leaves" that are 78-cm-long wires with tiny 24-g spheres at the ends. When charged, nearly all the charge resides on the spheres. If the wires each make a 26^{\circ} angle with the vertical, what total charge Q must have been applied to...
  15. S

    Electroscope Problem: Why the Foil Leaves were Unaffected by a Neutral Balloon

    A fully charged electroscope is touched with a neutral balloon. It is observed that the foil leaves of the electroscope are unaffected when the electroscope is touched w/ the balloon. Explain why the foil leaves were unaffected when the charged electroscope was touched by the neutral balloon...
  16. L

    Electroscope Charge Distribution

    Hey, I am helping out with a class and the students were given a question about an electroscope that is being charged by induction, and they have to label the charge distribution on a diagram. The diagram is drawn such that the conductive elements are separated - indicating a force between...
  17. M

    Is C the Correct Choice for Electroscope Question?

    Question is posted in paint doc... I think it is C, because polarization will occur sending neg charge down to the leaves making them repel. is this correct?
  18. Q

    Identifying Charges Using a Pith-ball Electroscope?

    Question: Can you use a pith-ball electroscope, to determine the charge of an unknown object? Is it possible?
  19. P

    Flame brought near charged electroscope

    Homework Statement When a flame is brought near a charged electroscope, the foil collapses. How is this explained? Homework Equations None The Attempt at a Solution Electrons are excited and given energy so distribute equally on the foil. Probably wrong. Please give correct...
  20. B

    Electroscope App Homework: Measuring Cloud Charge & Estimating Plane Field

    Homework Statement As you are lying on the beach this past summer, you watch in awe as a super huge strato-nimbo-cummulus storm cloud roll in. You pull out your iphone and use the "electroscope" App allowing you to measure the charge on the storm cloud. It reads +40C. You tell your bf/gf...
  21. A

    Where the energy to move electroscope leaves comes from?

    Hi, My question is about gold-leaf electroscope induction experiment as it's shown here: http://en.wikipedia.org/wiki/File:Electroscope_showing_induction.png To spread out leaves you need to spend some energy, I'd like to know where it comes from Thank you!
  22. Z

    Connecting wire from battery terminal to electroscope

    What would happen to an electroscope if a wire from the negative or positive terminal of a battery is touched to an electroscope? Will the electroscope deflect or will it do nothing?
  23. Z

    The gold leaf electroscope and the photoelectric effect

    The theory I have read When you charge an electroscope with a negatively charged rod, electrons are repelled to the bottom of the electroscope and the gold leaf rises. Then when you shine light above the fundamental frequency on the top plate of the electroscope, electrons are liberated from...
  24. J

    Electroscope; conceptual charge distribution questions

    Hello all, Q: If an electroscope is positively charged throughout (gold leaves are being repelled), and a very strong rod that is negatively charged, is progressively brought closer to the electroscope... How are the charges distributed? I think that as the negatively charged rod is...
  25. B

    Radiation and electroscope

    If ultraviolet radiation is shone onto a freshly-cleaned zinc cap of an uncharged leaf electroscope, explain why the emission of electrons will soon stop I understand it is about the photoelectric effect, but I am not sure why the emission will ever stop... Thank You in advance!:biggrin:
  26. S

    Charge leakage of an electroscope

    Homework Statement We are doing an experiment with a radioactive 226 Radium source, demonstrating the ionizing power of alpha radiation using an electroscope. This is one of the assignments: Charge an electroscope (what is an effective way?); you will notice the gradual discharging of the...
  27. G

    How does an electroscope work( test tomorrow )

    how does an electroscope work
  28. L

    Electroscope Properties (need explaination)

    So I came upon this problem on a quiz (didnt count for marks) about my Static Electricity Unit. It was like... An electroscope is negatively charged, with the leaf at an angle of about 45 degrees. A metal ball on an insulating handle is slowly brought to (but not touching) the plate of the...
  29. manjuvenamma

    Why only gold in leaf electroscope?

    Can some one tell me the speciality of gold for being used in gold leaf electrocscope in spite of being expensive when there are so many cheper metals that fit the bill as it appears to me?
  30. J

    Electrostatic force electroscope

    electroscope A large electroscope is made with “leaves” that are 78-cm-long wires with tiny 24-g spheres at the ends. When charged, nearly all the charge resides on the spheres. If the wires each make a 3.0E1° angle with the vertical (see figure), what total charge Q must have been applied to...
  31. P

    Positively charged rod to an uncharged electroscope

    Hi I was just wondering what the answer to the following question would be: If you bring a positively charged rod to an uncharged electroscope causing the vanes or leaves inside to diverge, are negative charges attracted to the knob of the electroscope or do positive charges repel to the...
  32. T

    Electroscope Forces: Calculating Total Charge Applied

    2. A large electroscope is made with "leaves" that are 78-cm-long wires with tiny 24-g spheres at the ends. When charged, nearly all the charge resides on the spheres. If the wires each make a 30 degree angle with the vertical, what total charge Q must have been applied to the electroscope...
  33. T

    Application of Coloumb's Law to electroscope

    Hi there, I am having a bit of difficulty with this problem dealing with a little more difficult application of Couloumbs Law. A large electroscope has two wires that are 75-cm long w/22g balls at the ends. When charged, all the charge resides on the balls (Q/2 for each ball) If the wires...
  34. U

    Electroscope question

    Ok, this is not really homework so maybe it needs to be moved some where else. Made a basic electroscope out of a wine bottle a while ago, charged up a balloon brought it close to the end of the scope and the leaves separated as expected, but when I quickly moved the balloon away from the...
  35. holly

    Electroscope Leaves Me Puzzled

    Electroscope "Leaves" Me Puzzled You know what's funny? By looking at the questions being posted, you can see students from all over plowing through the same topics at approximately the same time. People are getting to E&M now. Okay, Q. An electroscope is a simple device consisting of a...
  36. A

    Stabilizing the Leaves of an Electroscope

    Hello, I'm currently building an electroscope for a physics lab, and it's basically set up to be inside a glass jar, with two pieces of aluminum foil attached to a wire inside. The two pieces of foil move when charged objects come near, and it works well most of the time. However, when...