Multiple-Choice Homework Problem 8.1 For the resistor network to the right. R, =

Question

Multiple-Choice Homework Problem 8.1 For the resistor network to the right. R, = 10 Ohm, R2 = 20 Ohm, R:i = 25Ohm R4 = 15Ohm.R5 = 5 Ohm, and A Vo = 20V. Compute the current through Ri. Select One of the Following: 0.67A 0.33A 0.27A 5.1A 3.0A Multiple-Choice Homework Problem 8.2 An additional resistor is connected in parallel with a system of resistors connected to a battery. Assume a perfect battery. What will change as the additional resistor is connected? Select One of the Following: The voltage across the combination will decrease. The current through the original resistors will increase. The current through the original resistors will decrease. The current provided by the battery will increase. The current provided by the battery will decrease. Multiple-Choice Homework Problem 8.3 A resistor in a circuit consumes a power of 40W when the potential difference across it is 20V. What is the resistance of the resistor? Select One of the Following: 1 /2ft b) 1ft (c) 2ft (d) 5ft (e) 10ft Multiple-Choice Homework Problem 8.4 A 60W light bulb and a 100W light bulb are connected in a circuit. If the bulbs are connected in series, will the voltage be greater across the 60W bulb or across the 100W bulb? Select One of the Following: The potential difference across the 60W bulb will be larger. The potential difference across the 100W bulb will be larger. The potential difference across both bulbs will be the same.

Explanation / Answer

Ans 8.1

R1 and R2 is in serial conncetion their collective resistance R6= R1 + R2 = 10 + 20 = 30 ohm

R3 and R5 is in serial connection their collective resistance R7= R3 + R5 = 25 + 5 = 30 ohm

R6 and R7 is in parall connection their collective resistance R’ = R6R7/( R6 +R7)

= 30 * 30 /(30 + 30)

= 900/60

R’ = 15

This collective resistance R’ is connected in series with R4

Their collective resistance R = R4 + R’ = 15 + 15 = 30

Voltage V = V4 + V’

V = IR4 + IR’

20 = I(30)

I = 20/30 = 0.67 A

From this we can find V’ = IR’ = 0.67 * 15 = 10.05 V

10.05 will be the voltage on R6 and R7

The votage 10.05 V on R7 will be shared by R3 and R5 there will be same current

I3 = 10.05/R7 = 10.05/30= 0.335 A so answer is B

8.2

C) current through original resistors will decrease

8.3

P = V2/R

40 = 400/R

R = 400/40 = 10 ohm

8.4

B) Potential difference across 100 W bulb is larger

P = VI, bulbs in serias connection are resistors in serias connustion, they share voltage depending on resistance

Related Questions

Navigate

• Browse (All)
• Browse M
• Subjects

---

---

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