Physic CH11

Which one of the following choices will damp oscillations in an LC circuit?

• increase the inductance

• increase the emf

• increase the circuit resistance

• increase the capacitance

Which one of the following quantities remains constant for a given LC circuit?

• the energy stored in the capacitor

• the energy stored in the inductor

• the energy stored in the current flowing in the circuit

• the sum of the energy stored in the capacitor and that in the inductor

Which one of the following is the correct expression for the angular frequency of oscillation for an LC circuit?

• $\omega=LC$

• $\omega=\sqrt{LC}$

• $\omega=\frac{1}{LC}$

• $\omega=\frac{1}{\sqrt{LC}}$

Which of the following best describes the term forced oscillations?

• oscillations requiring an applied force

• oscillations that occur at a frequency other than the natural frequency of the circuit

• oscillations that occur in the windings of the inductor within an LRC circuit

• oscillations that occur at the natural frequency of the circuit

What is the SI unit for capacitive reactance?

• farad

• mho

• ohm

• cordel

Which of the following phrases best describes the term impedance?

• the resistance to the movement of charge carriers

• the generalized expression that combines all resistances within a circuit

• the resistance of a capacitor

• the internal resistance of a battery within an LRC circuit

An LC circuit has an inductance of 15 mH and a capacitance of 10 mF. At one instant the charge on the capacitor is 25 mC. At that instant the current is changing at the rate:

• 0 A/s

• 170 A/s

• 1.7 x 10^–7 A/s

• 3.8 x 10^–2 A/s

We desire to make an LC circuit that oscillates at 100 Hz using an inductance of 2.5 H. We also need a capacitance of:

• 1 F

• 1 mF

• $1\ \mu F$

• 1 nF

The text makes a comparison between an LC circuit and a block-spring system. In this analogy, the inductance corresponds to which of the following parameters for the block-spring system?

• mass

• spring constant

• velocity

• position

Which one of the following statements concerning the electrical and magnetic energies stored in an LC circuit is false? Assume for the following that f = 0.

• The maximum values of both the electric and magnetic energies is Q²/2C.

• The electric energy is at its minimum when the magnetic energy is zero joules.

• At a time t, the sum of the electric and magnetic energies is a constant equal to Q2/2C.

• The magnetic energy is at its maximum when the electric energy is zero joules.