After an action potential, the opening of additional voltage-gated ________ channels and the inactivation of sodium channels, cause the membrane to return to its resting membrane potential. a. sodium, b. potassium, c. calcium, d. chloride.

G. A step-down transformer has 525 turns in its secondary and 12 500 turns in its primary. If the potential difference across the primary is 3510 V, what is the potential difference across the secondary?

Find the potential outside a charged metal sphere (charge $Q$, radius $R$) placed in an otherwise uniform electric field $\vec{E}_0$. Explain clearly where you are setting the zero of the potential.

An enzyme and substrate are combined. The rate of reaction begins as shown in the following graph. To complete the graph, show the effect of increasing substrate concentration on a constant enzyme concentration. Show the effect of increasing temperature.

What new idea about light did Einstein use to explain the photoelectric effect? Why does the photoelectric effect exhibit a threshold frequency? Why does it not exhibit a time lag?

Authors use cause-and-effect relationships to show why events occur and why characters make decisions.

What do you think is the most significant cause and effect relationship in this selection?

Derive an expression for electric potential along the axis (the $x$-axis) of a disk with a hole in the center, as shown in the figure, where $R_1$ and $R_2$ are the inner and outer radii of the disk. What would the potential be if $R_1=0$ ?

An electron that is accelerated from rest through a potential difference $V_0$ has a de Broglie wavelength $\lambda_0$. What potential difference will double the electron's wavelength? (Express your answer in terms of $V_0$.)

Antihistamines block the effect of a chemical mediator called histamine, which is released during the inflammatory response. What effect does administering antihistamines have on the inflammatory response, and is the use of an antihistamine beneficial?

The ability of a muscle to generate tension immediately after stimulation is dependent on: a. myosin interaction with the M line, b. overlap of myosin and actin, c. actin attachments to the Z line, d. none of the above.

The cell found in bone that breaks it down is called an ________. a. osteoblast, b. osteocyte, c. osteoclast, d. osteon.

Sketch an approximate potential energy diagram for rotation about the carbon-carbon bond in 2,2-dimethylpropane. Does the form of the potential energy curve of 2,2-dimethylpropane more closely resemble that of ethane or that of butane?

List the series of events at the membrane that generate an action potential, including the contributions of chemically gated and voltage-gated ion channels.

In the following situation, is the substitution effect $\bold{larger, smaller}$, or the $\bold{same}$ size as the income effect? Explain your answer. Andreas works the same amount when his wage increases.