Physics Final Review

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

96 V

A magnet attracts...

Some substances and repels others

Relative to the electric force between two protons, the gravitational force between them is...

Weaker

The watt, the unit of power, is equal to the...

(volt)(ampere)

The resistance of a 30-W, 12-V light bulb is...

4.8 ohms

Three 12-V batteries cannot be connected to give a voltage for the set of...

6 V

In a simple series circuit containing two bulbs (resistors) of 1 ohm each are connected to a battery of 6 V. If the 6V battery is replaced by 12 V battery the current in the circuit will...

Double

Atoms and molecules are normally...

Electrically neutral

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...

16

The electrons in an atom...

Are some distance away from the nucleus

An object has a positive electric charge whenever...

It has a deficiency of electrons

Two 60-watt light bulbs are connected in parallel across a 120-V power line. The current in each bulb is...

0.5 A

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

12 A

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

2 A

A charge of +Q attracts a charge of -Q 1 cm away with a force of F. Another charge of +Q is placed next to the first one. The force on the charge of -Q is now...

2F

An electric iron draws a current of 15 A when connected to a 120-V power source. Its resistance is...

8 ohms

When a current passes through a resistance, the electric energy that is lost...

Becomes heat

The nucleus of an atom...

Contains most of the atom's mass

A kilowatt hour is a unit of...

Energy

A negative electric charge...

Interacts with both positive and negative charges

Which of the following statements is not true?

Protons and electron have equal masses

Two charges of +Q are 1 cm apart. If one of the charges is replaced by a charge of -Q, the magnitude of the force between them is...

The same