Chapter 3, Problem 127P

Suppose there are two transformers between your house and the high-voltage transmission line that distributes the power. In addition, assume your house is the only one using electric power. At a substation the primary of a step-down transformer (turns ratio = 1:23) receives the voltage from the high-voltage transmission line. Because of your usage, a current of 51.1 mA exists in the primary of the transformer. The secondary is connected to the primary of another step-down transformer (turns ratio = 1:36) somewhere near your house, perhaps up on a telephone pole. The secondary of this transformer delivers a 240-V emf to your house. How much power is your house using? Remember that the current and voltage given in this problem are rms values.

The human eye is most sensitive to light having a frequency of about 5.5 × 1014 Hz, which is in the yellow-green region of the electromagnetic spectrum. How many wavelengths of this light can fit across a distance of 2.2 cm?

A one-dimensional harmonic oscillator of mass m and angular frequency w is in a heat bath of temperature T. What is the root mean square of the displacement of the oscillator? (In the expressions below k is the Boltzmann constant.) Select one: ○ (KT/mw²)1/2 ○ (KT/mw²)-1/2 ○ kT/w O (KT/mw²) 1/2In(2)

Two polarizers are placed on top of each other so that their transmission axes coincide. If unpolarized light falls on the system, the transmitted intensity is lo. What is the transmitted intensity if one of the polarizers is rotated by 30 degrees? Select one: ○ 10/4 ○ 0.866 lo ○ 310/4 01/2 10/2

Before attempting this problem, review Conceptual Example 7. The intensity of the light that reaches the photocell in the drawing is 160 W/m², when 0 = 18°. What would be the intensity reaching the photocell if the analyzer were removed from the setup, everything else remaining the same? Light Photocell Polarizer Insert Analyzer

The lifetime of a muon in its rest frame is 2.2 microseconds. What is the lifetime of the muon measured in the laboratory frame, where the muon's kinetic energy is 53 MeV? It is known that the rest energy of the muon is 106 MeV. Select one: O 4.4 microseconds O 6.6 microseconds O 3.3 microseconds O 1.1 microseconds

The Lagrangian of a particle performing harmonic oscil- lations is written in the form L = ax² - Bx² - yx, where a, and are constants. What is the angular frequency of oscillations? A) √2/a B) √(+2a)/B C) √√Ba D) B/α

The mean temperature of the Earth is T=287 K. What would the new mean temperature T' be if the mean distance between the Earth and the Sun was increased by 2%? Select one: ○ 293 K O 281 K ○ 273 K 284 K

Two concentric current-carrying wire loops of radius 3 cm and 9 cm lie in the same plane. The currents in the loops flow in the same direction and are equal in magnitude. The magnetic field at the common center of the loops is 50 mT. What would be the value of magnetic field at the center if the direction of the two currents was opposite to each other (but their value is kept constant)? Select one: ○ 20 mT ○ 10 mT O 15 mT ○ 25 mT