Question 1

A battery with emf $$\varepsilon is $$connected in series with a resistor $$R$$, as shown in the first image. What is the current $$I in $$the circuit if the internal resistance of the battery is negligible?

Accepted Answer

$$I = \frac{\varepsilon}{R}$$

Question 2

The second image shows the symbol for a capacitor. Which of the following best describes the energy stored in a capacitor with capacitance $$C$$ and voltage $$V$$ across its plates?

Accepted Answer

$$U = \frac{1}{2}CV^2$

Question 3

Refer to the third image. If the plate separation in a parallel-plate capacitor is doubled while keeping the charge constant, what happens to the electric field between the plates?

Accepted Answer

The electric field remains the same.

Question 4

In the graph set shown in the seventh image, which graph correctly represents the relationship between the resistance $$R of a $$wire and its cross-sectional area $$A$$?

Accepted Answer

Graph d: $$R$$ decreases as $$A$$ increases, following $$R \propto \frac{1}{A}$$

Question 5

The eighth image shows a circuit with four capacitors: $$20\,\mu\mathrm{F}$$ and $$30\,\mu\mathrm{F} in $$parallel, each in series with a $$16\,\mu\mathrm{F}$$ capacitor. What is the equivalent capacitance of the entire circuit?

Accepted Answer

$$44\,\mu\mathrm{F}$$

Question 6

The ninth image shows a graph of $$F vs$$. $$1/r^2$$ for two interacting particles. If the force is positive for attraction and negative for repulsion, what does a straight line with a negative slope indicate?

Accepted Answer

The force is always repulsive.

Question 7

The tenth image shows a solenoid connected to a battery. Which of the following best describes the direction of the magnetic field inside the solenoid?

Accepted Answer

The magnetic field inside the solenoid points from left to right (in the direction of conventional current).

Question 8

The eleventh image shows a wire with radius $$R_w$$ carrying a current $$I_w$$ out of the page. What is the magnitude of the magnetic field at a distance $$R_w/2$$ from the center of the wire?

Accepted Answer

$$B = \frac{\mu_0$ I_w}{4\pi R_w}$$

Question 9

The twelfth image shows a conducting sphere of radius $$R$$ with charge $$-q_0$ surrounded by a thin shell of radius 2R$ with charge $$+$$q_0. $$What is the electric potential at a point just outside the shell ($$r \u003e 2R$$)?

Accepted Answer

$$V = 0$$

Question 10

The thirteenth image shows a hemispherical Gaussian surface of radius $$s$$ with a charge $$+Q$$ located a distance $$s/2$$ below the center of the flat face. Is the electric flux through the flat face greater than, less than, or equal to $$E_P \pi s^2$, where E_P$ is the field at the center?

Accepted Answer

Less than $$E_P \pi s^2$

Question 11

The fourteenth image shows the same hemispherical Gaussian surface, but now a charge $$-Q is $$placed a distance $$s/2$$ above the center. What happens to the electric flux through the curved surface?

Accepted Answer

The flux decreases.

Step-by-Step Physics Study Guide: Circuits, Capacitors, Fields, and Potentials

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