7. An electric current can perform work as long as there is a battery to produce current, some device to operate, and everything is connected in a complete path.
- An electric current can only flow when there is a closed path in which electrons can move. A complete path is required for charge to flow in a flashlight. Batteries must also be placed so that charge can flow negative to positive, passing through the bulb. This is an example of why an electric current can perform work as long as their is a complete path.
8. Formula of Ohm's law is V = IR (V = Voltage, I = Current, R = Resistance).
Amp or ampere is used for measuring current. It's the International Unit.
Potential difference is defined as the amount of work done in moving unit positive charge from one point to another.
It SI unit is volt.
Volt = Joule/Coulomb
9. A step down transformer has more turns of wire on the primary coil and less turns of wire on the secondary coil. This makes a smaller induced voltage in the secondary coil.
10. The gravity force has the same shape as Coulomb's law for electric charge forces, i.e., it is an inverse square law force that depends on the product of the two interacting sources. Coulomb's and gravitational forces are both directly proportional to the product of the body's charges and masses. Coulomb's and gravitational forces are both inversely proportional to the square of the distance between them. Both of these factors are central.
11. When two items rub together, such as your hair and the balloon, one loses part of its electrons to the other. As a result, one object is positively charged while the other is negatively charged. The opposites are then drawn to one other.
12. The heating of the steaming hot bath is actually having negative effects on the magnetism and magnetic field of the magnet. To explain further: As a result, heating a magnet breaks the domain walls, making it easier for magnetic domains that are normally aligned to spin and become misaligned. They are now less aligned and point in the opposite direction to their neighbors, resulting in a drop in magnetic field and magnetism loss.
13. When current flows, it generates a magnetic field surrounding the wire, which may be calculated using the right hand thumb rule. Magnetic fields can be represented by lines of force. These force lines are similar to rubber bands. When stretched, they try to shrink. When pressed against one other, they tend to push each other away.
14. When one bulb burns out, it creates an open circuit. Current does not flow in that branch, but it does flow in the parallel circuit's other branch. As a result, the other bulb continues to light. Also, the voltage across the other bulb remains constant, therefore the power given to it remains constant, and it continues to shine with the same brightness. What makes these lights parallel is because one light went out and the others remained bright. To give a better idea, here is a example, Assume that one lamp breaks and the other lamp continues to illuminate. Most homes have their lights wired in parallel. This means that they all receive the full voltage, and if one bulb fails, the others continue to operate. The current from the power source is larger than the current in each branch of a parallel circuit. This is the same case but with 3 lights, so therefore the light connected were parallel.
