Introduction to Physical Science: Ch 8

A system of 16 electrons, 11 protons, and 4 neutrons has a net charge of a. -8.0 × 10-19 C. b. 8.0 × 10-19 C. c. 1.6 × 10-19 C. d. -5.0 × 10-19 C. e. -1.6 × 10-19 C.

a. -8.0 × 10-19 C.

A component in an automobile 12-V electrical system has a resistance of 30 Ù. How much current is in the component when in operation? a. 0.4 A b. 360 A c. 42 A d. 2.5 A

a. 0.4 A

Three resistors, 40 Ù, 60 Ù, and 50 Ù, are wired in series and connected to a 120-V battery. What is the equivalent resistance for this circuit? a. 150 Ù b. 0.062 Ù c. 16 Ù d. 120000 Ù

a. 150 Ù

A ferromagnetic material loses this property above the ______________ temperature. a. Curie b. Coulomb c. domain d. Faraday

a. Curie

In a conductor, what moves? a. Electrons b. Neutrons c. Protons d. Quarks

a. Electrons

The electrical power dissipated by a resistance R is a. directly proportional to I2. b. directly proportional to I. c. none of these. d. inversely proportional to I.

a. directly proportional to I2.

The electric company charges a home on the basis of consumption of a. energy. b. power. c. voltage. d. resistance. e. current.

a. energy.

Voltage is defined as the ______________ per unit ______________. a. work; charge b. charge; current c. charge; work d. work; current

a. work; charge

A system of 11 protons and 9 neutrons has a net charge of a. 32.0 × 10-19 C. b. 17.6 × 10-19 C. c. -32.0 × 10-19 C. d. 11.0 × 10-19 C. e. -17.6 × 10-19 C.

b. 17.6 × 10-19 C.

If a negatively charged object is brought near a suspended, positively charged object, the suspended object will be a. repelled. b. attracted. c. charged more. d. discharged.

b. attracted.

Electric charge is measured in units of a. volts. b. coulombs. c. newtons. d. watts.

b. coulombs.

Ohms law gives the relationship between a. work and current. b. current and voltage. c. current and charge. d. force and current.

b. current and voltage.

The source of magnetism is a. magnetic monopoles. b. electrons. c. protons. d. polarization.

b. electrons.

For electrical safety, a. electrical shocks caused by 1 A of current are of no concern. b. fuses or circuit breakers are wired in series in circuits. c. fuses and circuit breakers are wired in parallel in circuits. d. fuses larger than the rated value can be placed in a circuit.

b. fuses or circuit breakers are wired in series in circuits.

Earths magnetic field a. is always in the same direction. b. is believed to arise from currents within the planets core. c. is always parallel to the planets surface. d. results from a huge bar magnet within the planet.

b. is believed to arise from currents within the planets core.

A generator is a device that converts a. chemical energy into electrical energy. b. mechanical energy into electrical energy. c. electrical energy into mechanical energy. d. heat energy into mechanical energy.

b. mechanical energy into electrical energy.

A(n) ______________ is an elementary particle with a charge of +1.6 × 10-19 C. a. electron b. proton c. atom d. neutron

b. proton

An ac voltage can be increased or decreased easily using a a. motor. b. transformer. c. fuse. d. battery. e. generator.

b. transformer.

A system of an electron and a neutron has a net charge of Choose one answer. a. +1.6 × 10-19 C. b. zero. c. -1.6 × 10-19 C. d. 3.2 × 10-19 C.

c. -1.6 × 10-19 C.

Which of the following would be the least conductive? a. Copper b. Salt water c. Glass d. Mercury

c. Glass

The unit for current is the a. coulomb. b. ohm. c. ampere. d. volt.

c. ampere.

An object that is negatively charged will a. attract a rubber rod stroked with fur. b. be polarized. c. attract a glass rod stroked with silk. d. none of these

c. attract a glass rod stroked with silk.

The direction of the magnetic field of a bar magnet is a. in any direction. b. toward the north pole. c. in the direction a compass would point. d. away from the south pole.

c. in the direction a compass would point.

For an ohmic conductor, current is a. independent of resistance. b. independent of voltage. c. inversely proportional to resistance. d. inversely proportional to voltage.

c. inversely proportional to resistance.

A(n) ______________ is an elementary particle with no charge. a. atom b. proton c. neutron d. electron

c. neutron

A system of an electron, a proton, and a neutron has a net charge of a. -1.6 × 10-19 C. b. 3.2 × 10-19 C. c. zero. d. +1.6 × 10-19 C.

c. zero.

A transformer with 400 turns on the primary coil is used to decrease the voltage from 3000 V to 120 V for home use. How many turns should be in the secondary coil? a. 3520 turns b. 10000 turns c. 400 turns d. 16 turns

d. 16 turns

An insulator has a positive electric charge of 4 × 10 -17 C. How many electrons were added or removed? a. 40 electrons added b. 250 electrons added c. 40 electrons removed d. 250 electrons removed

d. 250 electrons removed

Consider a wire at rest in a magnetic field as shown in the following figure. What will happen to the wire? a. The wire will be pushed perpendicular to the plane of the magnetic field. b. The wire will be pushed toward the north pole. c. A current will flow in the wire. d. Nothing will happen.

d. Nothing will happen.

The angle between true north and the direction in which a compass needle points is called the angle of a. dip. b. attack. c. inclination. d. declination.

d. declination.

A ferromagnetic material is magnetized by the alignment of a. atoms. b. poles c. single magnetic dipoles d. domains.

d. domains

A motor converts a. force into power. b. mechanical energy into electrical energy. c. electricity into magnetism. d. electrical energy into mechanical energy.

d. electrical energy into mechanical energy.

The unit of resistance is called a(n) a. watt. b. ampere. c. volt. d. ohm. e. coulomb.

d. ohm.

The mathematical form of Coulombs law is similar to that of a. the second law of motion. b. the second law of thermodynamics. c. Keplers second law. d. the law of gravitation.

d. the law of gravitation.

Magnetism results from a. the movement of magnetic charge. b. the movement of magnetic particles. c. Earths magnetic field. d. the movement of electric charge.

d. the movement of electric charge.

In a battery circuit with different resistors in parallel, a. the current is the same through each resistor. b. the total resistance is larger than the value of the largest resistor. c. the total resistance is larger than the value of the smallest resistor. d. the voltage is the same across each resistor.

d. the voltage is the same across each resistor.

If work is done on an electric charge, a ______________ is present. a. current b. transformer c. bigger charge d. voltage e. resistance

d. voltage

If the voltage across a resistor is doubled, the current will a. be cut in half. b. be cut to one-fourth. c. be quadrupled. d. remain the same. e. be doubled

e. be doubled

One ampere × one second is a unit of a. power. b. voltage. c. resistance. d. current. e. electric charge.

e. electric charge.

The abbreviation of the unit of resistance is a. S b. D c. Y d. P e. W

horseshoe looking symbol