Other Physics Answers

Consider two parallel plates of opposite charge separated by a distance of 0.016 m. The

electric field between the plates is uniform and has a magnitude of 6.00 x 104 V/m. The

plates are arranged such that the positively-charged plate is on top. All distances between

the plates are measured from the negatively-charged plate.

1) What is the magnitude of the potential difference between the two plates?

2) A -45.0 nC point charge is placed between the plates.

a) Toward which plate would the charge move?

b) What is the magnitude of the electric force experienced by the point charge?

c) If the point charge is placed exactly in the middle of the two plates, what is the

electric potential experienced by the point charge?

(1 μC = 10-6 C, 1 mC = 10-3 C)

Consider two point charges positioned on the x-axis. The first point charge carries +2.00

μC of charge and is placed at x = −1.00 m. The second charge carries -1.00 μC of charge

and is placed at x = 3.00 m.

1. How many protons make up the first charge? the second charge?

2. What is the force exerted by the positive charge on the negative charge?

3. In which direction is the force directed toward?

4. What would be the new value of the force if:

a. the first charge is doubled but the second charge is unchanged?

b. the first charge is unchanged but the second charge is doubled?

c. both charges are doubled?

d. both charges are halved?

Suppose that we replace the positive charge at x = −1.00 m with a -2.00 μC charge.

5. What is the magnitude of the force exerted by the charges on each other?

6. Is the new force attractive or repulsive?

Consider a parallel-plate capacitor whose plates have area 0.00450 m2 and separation

distance 0.000750 m.

1. Calculate the capacitance of this capacitor.

2. The capacitor is connected to a 12.0-V power source.

a. How much charge is stored in the capacitor plates?

b. What is the magnitude of the electric field produced between the plates of

the capacitor by the stored charge?

3. We want to construct a cylindrical capacitor with an equivalent capacitance. If

we are to use the same separation distance for the cylinders, then we can rewrite

the capacitance of the cylindrical capacitor to be

C =

2πε0L

ln d

.

a. How long should our cylindrical capacitor be if it is to have the same

capacitance as the parallel-plate capacitor?

The cross section of the iron conductor is a square of 1.2 mm. What is the length of the conductor if its resistance is 10 Ω? ρ = 10-7 Ωm.

Give an example of where energy might be lost in real life, resulting in slower

speeds than those calculated.

what is the kinetic energy of a 0.145kg baseball moving at 42 m/s?

Two point charges Q₁ = -25 micro coulombs and Q₂ = +50 micro coulombs are separated by a distance of 12 cm. The electric field at the point P is zero (and is to the left of Q₁). How far from (Q₁) is P?

Derive Boyle’s Law, Regnault’s Law for and Avogadro’s Hypothesis from Kinetic theory.

1.A plane-parallel capacitor has circular plates of radius r = 10 cm, separated by a distance d =1 mm. How much charge is stored on each plate when their electric potential difference has the value V = 100 V?

2. How much charge is stored in a capacitor consisting of two concentric spheres of radii 30 and 31 cm if the potential difference is 500 V?

3. What is the capacitance of the Earth, viewed as an isolated conducting sphere of radius 6370 km?

4. The space between the conductors of a long coaxial cable, used to transmit TV signals, has an inner radius a = 0.15 mm and an outer radius b = 2.1 mm. What is the capacitance per unit length of this cable?

5. In Fig. 25-30, the battery has a potential difference of V = 10.0 V and the five capacitors each have a capacitance of 10.0 µF. What is the charge on (a) capacitor 1 and (b) capacitor 2?