Question

Experiment: Charging by contact and induction:

Electrostatics Kit
Masking Tape
Monofilament Line
Paperclip
Wooden Block with Slit

In this experiment, you will charge pith balls by contact and induction.
- Tear one small piece of masking tape from the roll (approximately 5 cm).

-. Create a small, closed loop with the tape, leaving the sticky side on the outside of the loop.

-. Secure the looped tape to one of a side of the wooden block adjacent to the side with the slit.

-. Press the taped side of the wooden block onto a smooth wall (or the flat side of a counter or table top) with the slit pointing perpendicular to the wall and parallel to the floor.

-. Unwrap the outer layer of a paperclip.

-. Use the exposed end of the paperclip to poke a hole through the centers of two pith balls.

-. Thread one end of the monofilament line through one of the pith balls. Tie a knot on the end that you threaded through to keep the pith ball on the thread. Note: If the paperclip created a larger hole, three to five knots may need to be tied to secure the ball on the thread.

-. Repeat Step 7 on the other end of the monofilament line with the other pith ball.

-. Once the pith balls are secured on each end of the line, place the line in the slit of the wooden block. The pith balls should rest at the same height.

-. Remove any charge from the acetate strip (light blue and transparent) by grabbing it with your hand or rubbing it on a metal object like a door knob. This is called grounding.

-. Test for interactions between the acetate strip and both pith balls. Record observations of any interaction.

-. Charge the acetate strip by rubbing it with the cotton cloth.

-. Slowly bring the plastic strip close enough to the right pith ball so that it moves, but does not touch the plastic strip. Once movement of the pith ball is observed move the plastic strip away. Record your observations (e.g., how far away were the two objects, how fast did the pith ball move, in what direction did the pith ball move, etc.).

-. Slowly bring the plastic strip close enough to the left pith ball so that it moves, but does not touch the plastic strip. Once movement of the pith ball is observed move the plastic strip away. Record your observations.

-. Hold the monofilament line above the right pith ball and bring the ball into contact with the plastic strip.

-. Let the pith ball hang again and bring the plastic rod close to, but without touching the right pith ball. What kind of interaction is observed? Record your observations in Post-Lab Question 3.

-. Hold the line above the right pith ball and bring it close to the left pith ball. Observe what happens. Let the balls come into contact. How does that change the interaction?

-. Grab the pith balls to ground them and take away any charge they may have.

-. Charge the plastic rod again with the cotton.

-. Hold the line above the right pith ball with your pointer and middle finger. Bring the right pith ball close to the plastic rod, but do not let them touch. This time touch the left side of the ball (the one opposite of the rod) with your thumb. Let the ball hang again. Bring the right pith ball close to the left pith ball. Observe what happens.

1. Draw a diagram to show how Step 13 charged the right pith ball.

In addition to the diagram, I would like to know is my conclusion is correct: I believe the acetate strip contains a negative charge after being rubbed with the cotton, due to free electrons present on the surfaces. The charge on the acetate is negative? Will give 100% rating. Please and Thank you in advance!

Answer 1

Concept needed:-

Induction - It is the system of charging 2 materials with out touching them through bringing in contact with a impartial item.

Conduction- It is the manner of charging 2 materials by way of bringing them in contact with each other.

Solution:-

1) Pith Balls have become charged due to the procedure of Conduction. When it become rubbed with a cotton fabric, We furnished it with energy due to which a number of the electrons of the plastic strip became energized and have been knocked off the strip. This created a fee imbalance, as the poor electrons are knocked off the strip and for this reason a deficiency of bad charge is created. This manner charged the pith ball with tremendous rate and as a result it commenced performing like a magnet.

2)  We recognize that the proper pith ball become charged due to the subsequent remark.

> The ball and the plastic were drawn to every different.
>The balls were drawn to every other additionally.
These observations confirmed that the proper pith ball become charged.

3) The observations we observed that when step -sixteen, the ball and the plastic have been attracted to every other. As each of them were now not touched together , they should have been charged up with the aid of the procedure of induction, explained within the Concepts above. The plastic rod was charged. So while that came close to the ball, fees of contrary polarity as that of the rod got here close to the floor of ball this is towards the road, while fees of identical polarity as that of rod separated to the floor of ball faraway from the rod.

5) We realize that two items attract every other if they're having opposite polarity. This approach one of the ball is definitely charged, at the same time as other is negatively charged. Now we noticed that the plastic charged strip changed into delivered close to the proper ball. As explained in component 1 that the plastic strip turned into undoubtedly charged , so this means the proper pith ball is negatively charged and therefore the left pith ball is positively charged.