The electric force is directed from the negative particle to the positive particle
The electric force is zero.
The direction of the electric force cannot be determined.
The electric force is directed from the positive particle to the negative particle.
Correct answer is D
The electric force between two charged particles is always directed from the positive particle to the negative particle. This is because opposite charges attract each other, while like charges repel each other.
Which of the following is an example of a couple?
All of the above.
The forces that are applied to the handle of a screwdriver when you twist it.
The forces that are applied to a cross wench to loosen or tighten the lug nuts on a wheel of a car.
The forces that are applied to the steering wheel of a car when you turn it.
Correct answer is A
A couple is a pair of forces that are equal in magnitude but opposite in direction, and that are applied to a body at different points. The forces of a couple do not produce any translation, but they do produce a rotation.
Which of the following is NOT an example of elementary modern physics?
Classical mechanics
Quantum mechanics
Special relativity
Nuclear physics
Correct answer is A
Classical mechanics is a branch of physics that deals with the motion of macroscopic objects. It is based on the principles of Newton's laws of motion and is not considered to be part of elementary modern physics.
The other three options, quantum mechanics, special relativity, and nuclear physics, are all considered to be part of elementary modern physics because they deal with the behavior of matter and energy at the atomic and subatomic levels.
the magnetic field needs to be made stronger
the split rings should be replaced with slip rings
the number of turns of the armature coil needs to be decreased
the slip rings should be replaced with split rings
Correct answer is D
An AC generator uses slip rings to transfer the induced current smoothly to the circuit. A DC generator uses split rings to transfer the induced current to the circuit and also convert the induced AC into pulsating DC. So, to convert an AC generator into a DC generator, the slip rings needs to be replaced with split rings.
Which of the following materials is a good insulator?
Silver
Water
Rubber
Copper
Correct answer is C
Rubber is a good insulator because it does not allow electrons to flow through it easily. Copper, silver, and water are all good conductors of electricity.