Questions from Modern Physics

Q: A positive charge q is fixed at the point x = 0

A positive charge q is fixed at the point x = 0, y = 0, and a negative charge -2q is fixed at the point x = a, y = 0. (a). Show the positions of the charges in a diagram. (b). Derive an expression fo...

Q: A fuse is a device designed to break a circuit, usually

A fuse is a device designed to break a circuit, usually by melting when the current exceeds a certain value. What characteristics should the material of the fuse have?

Q: High-voltage power supplies are sometimes designed intentionally to have rather

High-voltage power supplies are sometimes designed intentionally to have rather large internal resistance as a safety precaution. Why is such a power supply with a large internal resistance safer than...

Q: The text states that good thermal conductors are also good electrical conductors

The text states that good thermal conductors are also good electrical conductors. If so, why don’t the cords used to connect toasters, irons, and similar heat-producing appliances get hot by conductio...

Q: A small particle has charge -5.00 µC and mass

A small particle has charge -5.00 µC and mass 2.00 × 10-4 kg. It moves from point A, where the electric potential is VA = +200 V, to point B, where the electric potential is VB = +800 V. The electric...

Q: The plates of a parallel-plate capacitor are 2.50

The plates of a parallel-plate capacitor are 2.50 mm apart, and each carries a charge of magnitude 80.0 nC. The plates are in vacuum. The electric field between the plates has a magnitude of 4.00 × 10...

Q: A spherical capacitor is formed from two concentric, spherical, conducting

A spherical capacitor is formed from two concentric, spherical, conducting shells separated by vacuum. The inner sphere has radius 15.0 cm and the capacitance is 116 pF. (a). What is the radius of th...

Q: The plates of a parallel-plate capacitor are 3.28

The plates of a parallel-plate capacitor are 3.28 mm apart, and each has an area of 9.82 cm2. Each plate carries a charge of magnitude 4.35 × 10-8 C. The plates are in vacuum. What is (a). the capacit...

Q: Which of the graphs in Fig. Q25.12 best illustrates

Which of the graphs in Fig. Q25.12 best illustrates the current I in a real resistor as a function of the potential difference V across it? Explain. Fig. Q25.12:

Q: A parallel-plate air capacitor of capacitance 245 pF has a

A parallel-plate air capacitor of capacitance 245 pF has a charge of magnitude 0.148 µC on each plate. The plates are 0.328 mm apart. (a). What is the potential difference between the plates? (b). W...