1. How will the 4.7 ohm resistor prolong the life of Ew? Imgaine S1 is closed bu

Question

1. How will the 4.7 ohm resistor prolong the life of Ew? Imgaine S1 is closed but S2 is open.

2. State the two purposes of the large resistor in parallel with S3 when S3 is open.

3. What is the reason that S3 is to be closed during the last stages of balancing (balancing Ax and As)?

4. Why is the metal bar connecting the two meter sticks NOT included as par of the distance of Ax or As?

5. True or False: When S1 is closed there is a path of low resistance allowing most current to bypass the galvanometer, thus protecting it.

6. True or False: When S1 is opened after the bridge is almost balanced, the small remaining current will not harm the galvanometer.

7. True or False: When S1 is opened after the bridge is almost balanced, the circuit is more sensitive than it was when S1 was closed.

8. True or False: When S3 is closed there is a path of low resistance allowing most current to bypass the galvanometer, thus protecting it.

9. True or False: When S3 is opened, the small remaining current will not harm the galvanometer as long as the bridge is almost balanced.

10. True or False: When S3 is closed, most current will travel through the adjacent resistor.

Slide wire potentiometer, galvanometer, 2 knife switches, tap switch, flat edged spade, SPDT (single pole double throw) switch, resistor from 4000 ohms to 6000 ohms, 4.7 ohm resistor, standard cell Es, 6 volt battery for Ew, unknown battery for Ex, two battery holders, and multimeter. You may use a resistance box in place of either resistance. NOTE: An SPDT is a switch which can be thrown to connect one circuit branch or another. CAUTION: Ideally, no current whatever should be drawn from Es. Practically, the current drawn must be kept to an absolute minimum. If you draw too much current, your answer will be wrong and you will lose points. The large resistor and the spade, tapped sparingly, minimize the current drawn from Ex and Es. The large resistor also protects the galvanometer. The small resistor by Ew reduces the current drawn from that battery. SUMMARY: You will determine the value of an unknown potential difference, Ex. PROCEDURE: Get your data sheet initialed by the instructor. Record the letter of Ex, and the number of the standard cell you are using. The value of the potential for the standard cell must be obtained

Explanation / Answer

1. If S1 is closed and 4.7 ohm is not there it will cause Ew to be short circuited. Which will discharge Ew very fast.

2. We have made all the arrangement such that when S3 is open Galvanometer will work as voltmeter to measure voltage so there should not be any current in G which is provided by very high resistance.

To prevent small current when Wheatstone is almost balanced

Since no current is to be drawn from Es we need to put up very high resistance.

3. When we need to find As we need to close S3 since Es is known we Can easily proportionate the value of As with unknown Ax.

4. Since that wire do not have resistance, metal bar, also called as shorting bar so it will not affect the values of Ax or As.

5. True

6. False

7. False

8. True

9. True

10. False

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.