Two flat conductors are placed with their inner faces separated by 9mm. If the surface charge density on inner face A is 69 pC/m^2 and on inner face B is -69 pC/m^2 calculate the electric potential difference using epsilon naught value of 8.85419x10^-12 C^2/Nm^2. Answer in units of V.


Answer 1


0.07 V


The electric field between two parallel plates is uniform, and its magnitude is given by


is the magnitude of the charge density on each face

is the vacuum permittivity

In this problem, we have

So, the electric field is

So now we can calculate the potential difference between the two plates, given by:

where is the distance between the two plates. Substituting, we find

Related Questions


Find the efficiency e of the oven. you will need to use the fact that 4.2 j of energy is required to raise the temperature of 1.0 ml of coffee by 1.0∘c .


Note that
V = 1.0 mL = 1 cm³ = 10⁻⁶ m³, the volume of water (coffee)
ρ = 1000 kg/m³, the density of water
c = 4.18 kJ/(kg-K), the specific heat of water

The mass of 1 mL of water (coffee) is
m = ρV = (1000 kg/m³)*(10⁻⁶ m³) = 10⁻³ kg

The heat required to raise the temperature by ΔT = 1.0 °C (1 K) is
Q₁ = m*c*ΔT
    = (10⁻³ kg)*(4.18 kJ/(kg-K))*(1 K) 
    = 4.18 x 10⁻³ kJ
    = 4.18 J

The actual heat used is Q₂ = 4.2J.

The efficiency is
e = Q₁/Q₂ = 4.18/4.2 = 0.995 or 99.5%
Note that this efficiency does not include the efficiency of the electrical circuitry and the magnetron.

Answer: 99.5%

The efficiency of the oven is .

Further Explanation:

The efficiency of the over is given as the ratio of the amount of energy provided to the coffee and the amount of energy consumed by the oven.

The amount of energy provided to the coffee by the oven is given as:

Here, is the amount energy gained by the coffee, is the volume of the coffee, is the specific heat capacity of the coffee and is the change in temperature.

Since the coffee uses of energy to raise the temperature of by . So, the specific heat capacity of the coffee is .

Substitute the values in above expression:

Now, the amount of energy supplied to the oven is:

Here,  is the power and is the time for which the oven is operated.

Substitute the values of   and in above expression.

The efficiency of the oven is given by:

Substitute the values in the above expression.

Thus, the efficiency of the oven is .

Learn More:

1.To what volume will a 2.33 l sample of gas expand if it is heated from

2.In the calorimetry experiment which energy will be calculated during the heat exchange if water is used

3.Suppose that the same amount of heat is added to two 10.0-g blocks

Answer Details:

Grade: College

Subject: Physics

Chapter: Specific heats

Keywords:  Efficiency of oven, coffee mug, 4.2 J, 1100 W, power, time, 45 s, input energy, ratio, energy consumed, heat coffee, temperature.


How many Newtons of force are required to stop a truck 2250 kg


U need a force of 27600N

How many minutes does light need to travel from the sun to Jupiter?


Light travels at a speed of 299,792 kilometers per second; 186,287 miles per second

Mercury it will take 193.0 seconds(3.2 minutes)

Venus it will take 360.0 seconds(6.0 minutes)

Earth it will take 499.0 seconds(8.3 minutes)

Mars  It will take 759.9 seconds(12.6 minutes)

Jupiter  It will take 2595.0 seconds(43.2 minutes)

Saturn it will take 4759.0 seconds(79.3 minutes)

Uranus it will take 9575.0 seconds(159.6 minutes)

Neptune it will take 14998.0 seconds(4.1 hours)

Pluto  it will take 19680.0 seconds(5.5 hours)


A small bolt with a mass of 33.0 g sits on top of a piston. The piston is undergoing simple harmonic motion in the vertical direction with a frequency of 3.05 Hz. What is the maximum amplitude that the piston can oscillate without the bolt losing contact with the piston's surface?





the bolt loses contact with the piston only when acceleration due to gravity equals acceleration of piston

ω² * A = g where ω is angular velocity, A amplitude, g acceleration due to gravity

ω is given by 2πf, ω² is 4π²f²

A= g/4π²f² depending on the value of g used either 10m/s² or 9.8m/s²,

i used 10m/s² in this answer

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