Chapter 8 Quiz

Internal energy of a body is the sum of ........................... and .............................

Select all options that apply.

• kinetic energy due to motion of particles

• thermal energy due to heat absorbed by particles

• potential energy due to intermolecular forces

• potential energy due to motion of particles

• electric energy due to electrostatic forces between atoms

Which statement is false about thermal equilibrium?

• When two objects are in thermal equilibrium, they have the same temperature.

• When two objects are at the same temperature, no transfer of thermal energy occurs between them.

• When an object at 65°C is left untouched in a room for a long time, it will eventually reach room temperature.

• No net transfer of thermal energy occurs between two objects in thermal equilibrium.

A metal rod is heated at one end. Which statement best describes the conduction of heat through the metal rod?

• Atoms vibrate and hit atoms at the cold end.

• Atoms move from the hot end and hit electrons at the cold end.

• Free electrons move from the hot end and hit atoms further along the rod.

• Free electrons vibrate and pass energy to free electrons along the rod.

Metals in the liquid state ............................................................

• are poor thermal conductors as liquids are generally poorer thermal conductors than solids

• are poor thermal conductors as the free electrons in metals disappear upon melting, so liquid metals are similar to non-metals

• are good thermal conductors as liquids are generally better thermal conductors than solids

• are good thermal conductors as they have free electrons which move very fast through the metal and transfer energy easily

In this kitchen appliance, the heating element is at the top of the box while the food is placed on top of the metal grill at the bottom of the box. Heat is transferred from the heating element to the food via .........................................

• Conduction

• Convection

• Radiation

• Not possible to tell

The diagram shows the inside of an oven. Which statement is false about this oven?

• Thermal energy is transferred from the heating elements to the food via conduction.

• Thermal energy is transferred from the heating elements to the food via convection.

• Thermal energy is transferred from the heating elements to the food via radiation.

A freezer is used to keep food cold. It is advantageous to paint the outside of the freezer ................... because ........................................................................ for the freezer to best perform its function.

• Black because black is a good emitter of radiation.

• Black because black is a good absorber of radiation.

• The color of the outside of the freezer does not matter.

• White because white is a good reflector of radiation.

• White because white is a poor emitter of radiation.

Is the convection current drawn correctly in the diagram?

• Yes

• No

• A convection current will not be formed in this scenario

Can a convection current be set up in this beaker of water if the water is being cooled at Y?

• Yes

• No

• Not possible to tell

The main reason for silvering in a vacuum flask is to ............................................................................

• Prevent heat transfer via radiation

• Reduce heat transfer via radiation

• Prevent heat transfer via conduction

• Reduce heat transfer via conduction