Question 1

Which equation correctly expresses the electric power dissipated in a resistor?

Accepted Answer

$$P = IV$$

Question 2

Three identical lightbulbs are connected as shown in the circuit. What happens to the brightness of bulb 1 when switch S is closed?

Accepted Answer

It remains the same.

Question 3

Which of the following statements about the pictured circuit is true?

Accepted Answer

All of the above.

Question 4

In an RC circuit, the time constant $$	au is $$given by:

Accepted Answer

$$	au = RC$$

Question 5

A battery, a 10 $$\Omega$$ resistor, and a capacitor form an RC circuit. If the time constant is 1.0 ms, what is the capacitance of the capacitor?

Accepted Answer

1.0 $$\muF$$

Question 6

A proton is moving upward in a magnetic field directed to the right. In what direction is the resulting force?

Accepted Answer

Out of the screen.

Question 7

The magnetic field 2 cm from a long straight wire is 16 $$\muT. $$What is the magnetic field at 8 cm from the wire?

Accepted Answer

2 $$\muT$$

Question 8

The current through a solenoid is tripled. By what factor does the magnetic field it generates change?

Accepted Answer

3

Question 9

Why is a bar magnet magnetized?

Accepted Answer

The magnetic moments of the atoms in the magnet were aligned by an external magnetic field and retained that alignment afterwards.

Question 10

According to Ampère’s Law, what is the magnetic field inside the hollow area ($$r \u003c a) of an $$infinite hollow cylinder carrying current $$I$$?

Accepted Answer

$$0$$

Question 11

What is the magnetic field outside the cylinder ($$r \u003e b) $$for an infinite hollow cylinder carrying current $$I$$?

Accepted Answer

$$\frac{\mu_0$ I}{2 \pi r}$$

Question 12

Which of the following is NOT a way to induce an emf in a circuit according to Faraday’s Law?

Accepted Answer

Changing the resistance of the circuit.

Question 13

A wire loop is placed in a region where the magnetic field is increasing into the screen. What is the direction of the induced current?

Accepted Answer

Counter-clockwise

Question 14

The self-inductance $$L of a $$coil is defined as:

Accepted Answer

$$L = \frac{\Phi_B}{I}$$

Question 15

In an RL circuit, the time constant $$	au is$$:

Accepted Answer

$$	au = \frac{L}{R}$$

Question 16

A current loop generates a magnetic field with what spatial dependence?

Accepted Answer

$$\frac{1}{r^3$}$$

Question 17

Which property of electrons is responsible for the magnetic dipole moment in atoms?

Accepted Answer

Spin

Question 18

What happens to the domains in a ferromagnetic material when an external magnetic field is applied?

Accepted Answer

Domains aligned with the field grow larger while those not aligned shrink.

Question 19

In an RL circuit, what happens to the current immediately after the switch is closed?

Accepted Answer

The current starts at zero and increases gradually.

Physics Fundamentals 2: Electric Circuits, RC Circuits, and Magnetism Study Guidance

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