Questions from Modern Physics

Q: A uniform wire of resistance R is cut into three equal lengths

A uniform wire of resistance R is cut into three equal lengths. One of these is formed into a circle and connected between the other two (Fig. E26.1). What is the resistance between the opposite ends...

Q: When the polarity of the voltage applied to a dc motor is

When the polarity of the voltage applied to a dc motor is reversed, the direction of motion does not reverse. Why not? How could the direction of motion be reversed?

Q: If two resistors R1 and R2 (R2 > R1) are

If two resistors R1 and R2 (R2 > R1) are connected in parallel as shown in Fig. Q26.6, which of the following must be true? In each case justify your answer. Fig. Q26.6: / / (a). I1 = I2. (b). I3...

Q: A machine part has a resistor X protruding from an opening in

A machine part has a resistor X protruding from an opening in the side. This resistor is connected to three other resistors, as shown in Fig. E26.2. An ohmmeter connected across a and b reads 2.00 &Ic...

Q: A triangular array of resistors is shown in Fig. E26.

A triangular array of resistors is shown in Fig. E26.5. What current will this array draw from a 35.0-V battery having negligible internal resistance if we connect it across Fig. E26.5: (a). ab;...

Q: For the circuit shown in Fig. E26.6 both meters

For the circuit shown in Fig. E26.6 both meters are idealized, the battery has no appreciable internal resistance, and the ammeter reads 1.25 A. Fig. E26.6: (a). What does the voltmeter read? (b)...

Q: For the circuit shown in Fig. E26.7 find the

For the circuit shown in Fig. E26.7 find the reading of the idealized ammeter if the battery has an internal resistance of 3.26 Ω. Fig. E26.7:

Q: Find the emfs E1 and E2 in the circuit of Fig.

Find the emfs E1 and E2 in the circuit of Fig. E26.26, and find the potential difference of point b relative to point a. Fig. E26.26:

Q: In the circuit shown in Fig. E26.27, find

In the circuit shown in Fig. E26.27, find Fig. E26.27: (a). the current in the 3.00-Ω resistor; (b). the unknown emfs

Q: In the circuit shown in Fig. E26.28, find

In the circuit shown in Fig. E26.28, find Fig. E26.28: (a). the current in each branch and (b). the potential difference Vab of point a relative to point b.