Question 1

The work done on an ideal gas system in an isothermal process is -400 J. What is the change in internal (thermal) energy of the gas?

Accepted Answer

For an ideal gas undergoing an isothermal process, the temperature remains constant. According to the first law of thermodynamics, if the work is done on the system and there's no change in temperature, the internal energy remains unchanged. Therefore, the change in internal energy is 0 J.

Question 2

A solid aluminum cube rests on a wooden table in a region where a uniform external electric field is directed straight upward. What can we say concerning the charge on the top surface of the
Cube?

Accepted Answer

In a conductor like aluminum, free electrons will move in response to an external electric field. Since the field is directed upward, electrons will move to the bottom surface, leaving the top surface positively charged.

Question 3

During an isochoric process, the internal (thermal) energy of a gas decreases by 50 J. How much heat is added to the gas during this process?

Accepted Answer

In an isochoric process, the volume of the gas remains constant, meaning no work is done on or by the gas. Therefore, any change in internal energy is due solely to heat exchange. If the internal energy decreases by 50 J, it means 50 J of heat was removed from the gas, hence -50 J.

Question 4

The potential difference between the plates of an ideal air-filled parallel-plate capacitor with a plate separation of 6.0 cm is 60 V. What is the strength of the electric field between the plates of this
Capacitor?

Accepted Answer

The electric field (E) between the plates of a parallel-plate capacitor is given by the formula E = V/d, where V is the potential difference and d is the separation between the plates. Here, V = 60 V and d = 0.06 m, so E = 60 V / 0.06 m = 1000 V/m.

Question 5

A cyclic process is carried out on an ideal gas such that it returns to its initial state at the end of a cycle, as shown in the  pV  diagram in the figure. If the process is carried out in a clockwise sense around the enclosed area, as shown on the figure, then the change of internal energy over the full cycle

Accepted Answer

The answer of A cyclic process is carried out on...

Question 6

An ideal gas is compressed isobarically to one-third of its initial volume. The resulting pressure will be

Accepted Answer

In an isobaric process, the pressure remains constant even if the volume changes. Therefore, compressing the gas to one-third of its initial volume does not change the pressure.

Question 7

A conductor is placed in a steady external electric field. Which of the following statements are correct for this situation? (There could be more than one correct choice.)

Accepted Answer

The answer of A conductor is placed in a steady...

Question 8

A negatively-charged plastic rod is brought close to (but does not touch) a neutral metal sphere that is connected to ground. After waiting a few seconds, the ground connection is removed
(without touching the sphere), and after that the rod is also removed. The sphere is now

Accepted Answer

When a negatively charged rod is brought near a neutral metal sphere, electrons in the sphere are repelled away from the side closest to the rod due to repulsion. This leaves the side of the sphere nearest to the rod positively charged. If the sphere is grounded while this is happening, electrons will flow from the ground into the sphere to neutralize the positive charge on the side farthest from the rod, effectively removing some of the sphere's electrons. When the ground connection is removed, the sphere cannot regain the lost electrons, and when the rod is removed, the sphere remains positively charged because it has fewer electrons than protons.

Question 9

The second law of thermodynamics leads us to conclude that

Accepted Answer

The second law of thermodynamics states that the total entropy of an isolated system can never decrease over time, and is constant if and only if all processes are reversible. In practical terms, this means that the disorder, or randomness, of the universe (or any isolated system) tends to increase over time, leading to the conclusion that disorder in the universe is increasing with the passage of time.

Question 10

In a given reversible process, the temperature of an ideal gas is kept constant as the gas is compressed to a smaller volume. Which one of the following statements about the gas is correct?

Accepted Answer

The answer of In a given reversible process, the temperature...

Question 11

Which one of the following is a true statement?

Accepted Answer

A) This statement is false because it is possible to transfer heat from a cooler to a hotter body with the help of external work, as in a refrigerator. B) The second law of thermodynamics is not a consequence of the first law; it is an independent principle that introduces the concept of entropy. C) This statement is false because it is entirely possible to convert work into heat, as seen in frictional processes. D) This statement is false because heat spontaneously flows from a hot body to a cold one in natural processes, and not the other way around without external work. Therefore, all of these statements are false.

Question 12

A plastic rod is charged up by rubbing a wool cloth, and brought to an initially neutral metallic sphere that is insulated from ground. It is allowed to touch the sphere for a few seconds, and then
Is separated from the sphere by a small distance. After the rod is separated, the rod

Accepted Answer

When the charged rod touches the neutral metallic sphere, it transfers some of its charge to the sphere. If the rod was negatively charged, the sphere becomes negatively charged as well, causing the rod to be repelled by the sphere once they are separated.

Question 13

An ideal gas is compressed isothermally to one-third of its initial volume. The resulting pressure will be

Accepted Answer

In an isothermal process for an ideal gas, the pressure and volume are inversely proportional (Boyle's Law: P1V1 = P2V2). If the volume is reduced to one-third, the pressure will increase to three times its initial value.

Question 14

Electrically neutral objects cannot exert an electrical force on each other, but they can exert a
gravitational force on each other.

Accepted Answer

The answer of Electrically neutral objects cannot exert an electrical...

Question 15

An ideal gas undergoes an adiabatic process while doing 25 J of work. What is the change in the internal (thermal) energy of the gas?

Accepted Answer

In an adiabatic process, there is no heat exchange with the surroundings. The work done by the gas results in a decrease in its internal energy. According to the first law of thermodynamics, ΔU = Q - W, where ΔU is the change in internal energy, Q is the heat added to the system, and W is the work done by the system. Since Q = 0 for an adiabatic process and W = 25 J, ΔU = 0 - 25 J = -25 J.

Question 16

If two objects are electrically attracted to each other,

Accepted Answer

The answer of If two objects are electrically attracted to...

Question 17

During an isothermal process, 5.0 J of heat is removed from an ideal gas. What is the work done by the gas in the process?

Accepted Answer

In an isothermal process for an ideal gas, the work done by the gas is equal to the heat added to the system. If heat is removed, the work done is negative and equal in magnitude to the heat removed. Therefore, if 5.0 J of heat is removed, the work done by the gas is -5.0 J.

Question 18

When a gas expands adiabatically,

Accepted Answer

In an adiabatic expansion, a gas does work on its surroundings, which results in a decrease in its internal (thermal) energy since no heat is exchanged with the surroundings.

Question 19

In an adiabatic compression, 200 J of work is done on a gas. What is the change in internal (thermal) energy of the gas during this compression?

Accepted Answer

In an adiabatic process, there is no heat exchange with the surroundings. Therefore, the work done on the gas directly increases its internal energy by the same amount, which is 200 J.

Question 20

An important feature of the Carnot cycle is that

Accepted Answer

The Carnot cycle is a theoretical model that defines the maximum possible efficiency for any heat engine operating between two temperatures. No real engine can exceed the efficiency of a Carnot engine operating between the same two temperatures.

Quiz 2: Describing Motion: Kinematics in One Dimension