Exam 21: Alternating-Current Circuits and Electromagnetic Waves

When a 47-μF capacitor is attached to an AC source,its capacitive reactance is 42.0 Ω.If instead a 150-μF capacitor is attached to the same source,what will be its capacitive reactance?

In an AC circuit operating at a frequency where the phase angle with respect to the current is 30°,what happens to the phase angle if the capacitance of the circuit is increased?

Temperature variation of different parts of a person's body can be detected by analyzing the emission pattern of which type of electromagnetic radiation?

A 400-Ω resistor and a capacitor are connected in parallel across a 300-Hz source.If the amplitude of the current in the resistor is equal to that in the capacitor,what is the value of the capacitance?

A 400-Ω resistor and an inductor are connected in parallel across a 300-Hz source.If the amplitude of the current in the resistor is equal to that in the inductor,what is the value of the inductance?

The electric field, ,in an electromagnetic wave is oriented in what direction with respect to its associated magnetic field, ?

What is the phase angle of an AC series circuit that is constructed of a 14.5-Ω resistor along with 16.5-Ω inductive reactance and 9.41-Ω capacitive reactance?

The Earth is 1.49 × 10¹¹ m from the Sun.If the solar radiation at the top of the Earth's atmosphere is 1 340 W/m²,what is the total power output of the Sun?

Consider an AC series circuit containing a coil,capacitor,and resistance.Doubling the frequency will change the capacitive reactance by what factor?

Find the frequency of x-rays of wavelength 1.75 × 10−¹⁰ m.(c = 3 × 10⁸ m/s)

Peak values for a neodymium-glass laser are 600 J for 1.00 nanosecond.If the cross-section of the laser beam is 1.10 cm²,what are the maximum values of E and B? (µ₀ = 4π × 10−⁷ T⋅m/A,c = 3.00 × 10⁸ m/s)

In an AC series circuit,the voltage in the inductor differs in phase with the voltage in the capacitor by what angle?

An AC series circuit has 16.5 Ω resistance,12.8 Ω inductive reactance and 8.27 Ω capacitive reactance.If an effective (rms)emf of 145 V is applied,what is the effective (rms)current value?

An electromagnetic wave is made up of which of the following oscillating quantities?

An ideal transformer is one that:

An ultraviolet light wave has a wavelength of 300 nm and speed of 1.96 × 10⁸ m/s through a transparent medium.What is the frequency of this wave in the medium? (1 nm = 10−⁹ m and c = 3.00 × 10⁸ m/s)

The frequency in an AC series circuit is quadrupled.By what factor does this change the capacitive reactance?

In order to keep its food hot,a restaurant will place it under which type of lamp?

An AC voltage source,with a peak output of 122 V,is connected to a 54.0-Ω resistor.What is the rate of energy dissipated due to heat in the resistor?

A radar pulse returns 5.0 × 10−⁴ seconds after it is sent out,having been reflected by an object.What is the distance between the radar antenna and the object? (c = 3.00 × 10⁸ m/s)