When a positive charge moves in the direction of the electric field, what happens to the electrical potential energy associated with the charge?

It increases.
It decreases.
It remains the same.
It sharply increases, and then decreases.

A

How is a motor's mechanical energy able to perform mechanical work?

Mechanical energy is converted into electrical energy.
A current is generated by a rotating loop in a magnetic field.
Electrical energy is converted into a magnetic force.
A shaft connected to the rotating coil is attached to some external device.

D

Which of the following statements about electromagnetic radiation is true?

It transfers energy to objects in the path of the electromagnetic waves.
It can be converted to other energy forms.
It transports the energy of electromagnetic waves.
all of the above

D

What daughter isotopes are produced when a neutron combines with a nucleus of 235/92 U? Assume that three neutrons are also produced in the reaction.

A. 140/56 Ba, 95/36 Kr
B. 142/56 Ba, 93/36 Kr
C. 140/56 Ba, 93/36 Kr
D. 141/56 Ba, 94/36 Kr

B

Which interaction of nature binds atoms and molecules by attracting unlike charges and repulsing like charges?

strong
weak
electromagnetic
gravitational

C

Wrong

Correct
Correct
Wrong. You forgot the extra neutrons released.
Correct

Is 1 D and 4 D also?

When a positive charge moves in the direction of the electric field, the electrical potential energy associated with the charge decreases.

To answer the first question, when a positive charge moves in the direction of the electric field, its electrical potential energy decreases. The electric potential energy associated with a charge is given by the equation U = qV, where U is the potential energy, q is the charge, and V is the electric potential. Since the charge is positive and is moving in the same direction as the electric field, it is moving from a region of higher electric potential to a region of lower electric potential. Therefore, the potential energy decreases.

To answer the second question, a motor's mechanical energy is able to perform mechanical work because a current is generated by a rotating loop in a magnetic field. This is known as electromagnetic induction. When the loop rotates, it cuts through the lines of a magnetic field, which induces an electric current in the loop. This current can then be used to power the motor and perform mechanical work.

Regarding the statement about electromagnetic radiation, the correct answer is that all of the above statements are true. Electromagnetic radiation transfers energy to objects in the path of the electromagnetic waves, it can be converted to other forms of energy (such as electrical or thermal), and it transports the energy of electromagnetic waves through space.

For the question about the daughter isotopes produced when a neutron combines with a nucleus of 235/92 U and three neutrons are also produced in the reaction, the correct answer is option B. The daughter isotopes produced are 142/56 Ba (Barium) and 93/36 Kr (Krypton).

Finally, the interaction of nature that binds atoms and molecules by attracting unlike charges and repulsing like charges is the electromagnetic interaction. This interaction is responsible for the forces between charged particles and is crucial for the stability and structure of atoms and molecules.