Question 1

The voltage needed to produce a current of 8 A in a resistance of 12 ohms is

Accepted Answer

A) 0.67 V. 
B) 1.5 V. 
C) 4 V. 
D) 96 V. 
A) 0.67 V. 
B) 1.5 V. 
C) 4 V. 
D) 96 V.

Question 2

An object has a positive electric charge whenever

Accepted Answer

A) it has an excess of electrons. 
B) it has a deficiency of electrons. 
C) the nuclei of its atoms are positively charged. 
D) the electrons of its atoms are positively charged. 
A) it has an excess of electrons. 
B) it has a deficiency of electrons. 
C) the nuclei of its atoms are positively charged. 
D) the electrons of its atoms are positively charged.

Question 3

The current in a 24-W, 12-V light bulb is

Accepted Answer

A)  0.5 A. 
B)  2 A. 
C)  12 A. 
D)  288 A. 
A)  0.5 A. 
B)  2 A. 
C)  12 A. 
D)  288 A.

Question 4

The current in a 20-ohm electric heater operated at 240 V is

Accepted Answer

A)  0.083 A. 
B)  12 A. 
C)  2880 A. 
D)  4800 A. 
A)  0.083 A. 
B)  12 A. 
C)  2880 A. 
D)  4800 A.

Question 5

The primary coil of a transformer has 200 turns and its secondary coil has 50 turns, and the current in the secondary coil is 40 A.When a 12-V alternating current is applied to the primary coil of the transformer, the secondary voltage will be

Accepted Answer

A) 3 V. 
B) 6 V. 
C) 24 V. 
D) 48 V. 
A) 3 V. 
B) 6 V. 
C) 24 V. 
D) 48 V.

Question 6

Two charges, one positive and the other negative, are initially 2 cm apart and are then pulled away from each other until they are 8 cm apart.The force between them is now smaller by a factor of

Accepted Answer

A) 2. 
B) 4. 
C) 16. 
D) 32. 
A) 2. 
B) 4. 
C) 16. 
D) 32.

Question 7

The conventional unit of battery capacity is the ampere-hour, which is actually a unit of

Accepted Answer

A) energy. 
B) power. 
C) potential difference. 
D) electric charge. 
A) energy. 
B) power. 
C) potential difference. 
D) electric charge.

Question 8

The primary coil of a transformer is connected to a source of alternating current of voltage V.The voltage of the secondary current is

Accepted Answer

A) lower than V. 
B) equal to V. 
C) higher than V. 
D) Any of these choices could be correct, depending on the ratio of turns in the transformer coils. 
A) lower than V. 
B) equal to V. 
C) higher than V. 
D) Any of these choices could be correct, depending on the ratio of turns in the transformer coils.

Question 9

When a magnetized iron bar is strongly heated, its magnetic field

Accepted Answer

A) becomes weaker. 
B) becomes stronger. 
C) reverses its direction. 
D) is unchanged. 
A) becomes weaker. 
B) becomes stronger. 
C) reverses its direction. 
D) is unchanged.

Question 10

A current-carrying loop in a magnetic field always tends to turn until the plane of the loop is

Accepted Answer

A) parallel to the field. 
B) perpendicular to the field. 
C) either parallel or perpendicular, depending on the direction of the current. 
D) at a 45-degree angle with the field. 
A) parallel to the field. 
B) perpendicular to the field. 
C) either parallel or perpendicular, depending on the direction of the current. 
D) at a 45-degree angle with the field.

The voltage needed to produce a current of 8 A in a resistance of 12 ohms is

An object has a positive electric charge whenever

The current in a 24-W, 12-V light bulb is

The current in a 20-ohm electric heater operated at 240 V is

The primary coil of a transformer has 200 turns and its secondary coil has 50 turns, and the current in the secondary coil is 40 A.When a 12-V alternating current is applied to the primary coil of the transformer, the secondary voltage will be

Two charges, one positive and the other negative, are initially 2 cm apart and are then pulled away from each other until they are 8 cm apart.The force between them is now smaller by a factor of

The conventional unit of battery capacity is the ampere-hour, which is actually a unit of

The primary coil of a transformer is connected to a source of alternating current of voltage V.The voltage of the secondary current is

When a magnetized iron bar is strongly heated, its magnetic field

A current-carrying loop in a magnetic field always tends to turn until the plane of the loop is

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Exam 6: Electricity and Magnetism

The voltage needed to produce a current of 8 A in a resistance of 12 ohms is

An object has a positive electric charge whenever

The current in a 24-W, 12-V light bulb is

The current in a 20-ohm electric heater operated at 240 V is

The primary coil of a transformer has 200 turns and its secondary coil has 50 turns, and the current in the secondary coil is 40 A.When a 12-V alternating current is applied to the primary coil of the transformer, the secondary voltage will be

Two charges, one positive and the other negative, are initially 2 cm apart and are then pulled away from each other until they are 8 cm apart.The force between them is now smaller by a factor of

The conventional unit of battery capacity is the ampere-hour, which is actually a unit of

The primary coil of a transformer is connected to a source of alternating current of voltage V.The voltage of the secondary current is

When a magnetized iron bar is strongly heated, its magnetic field

A current-carrying loop in a magnetic field always tends to turn until the plane of the loop is

The Scientific Method

Motion

Energy

Energy and the Future

Matter and Heat

Waves

The Nucleus

The Atom

The Periodic Law

Crystals, Ions, and Solutions

Chemical Reactions

Organic Chemistry

Atmosphere and Hydrosphere

The Rock Cycle

The Evolving Earth

The Solar System

The Stars

The Universe

Filters