Going back to the blog I made 6 years ago, seeing that people, students are still visiting this blog, I’ve decided to show you guys more about me, my interest and my journey.
This is a question that confuses many, especially those who are just beginning to learn about electricity.
Should heating element have high resistance or low resistance? Before that, follow me, here is the basic understanding.
Q) What are the possible fault in electrical appliances?
The fault could be due to:
- Conductors (e.g. wires, terminals, components) at hot or near full mains potential breaking, bending or detaching and touching the casing of the appliance
- Breakdown of insulation. For instance, insulation on cores of the power flex could become damaged inside an appliance or insulating spacers could become dislodged. Also, metal parts such as screws or nuts which have come undone could bridge the gap between hot and the metal casing
- Making contact with a power cable when drilling through a wall
Q) What is a hot / live wire?
Current flows out from source through this wire to an appliance.
Q) What is a neutral wire?
The neutral wire is at a voltage close to or equal to ground. Current which flows to an appliance via the hot wire returns via the neutral core in a cable
Do take note of the difference between earth wire, neutral wire, grounding too 🙂
Nervous System Checklist O Levels
Candidates should be able to:
(a) state the relationship between receptors, the central nervous system and the effectors
(b) describe the structure of the eye as seen in front view and in horizontal section
(c) state the principal functions of component parts of the eye in producing a focused image of near
and distant objects on the retina
(d) describe the pupil reflex in response to bright and dim light
(e) state that the nervous system – brain, spinal cord and nerves, serves to co-ordinate and regulate
(f) outline the functions of sensory neurones, relay neurones and motor neurones
(g) discuss the function of the brain and spinal cord in producing a co-ordinated response as a result
of a specific stimulus in a reflex action
(h) define a hormone as a chemical substance, produced by a gland, carried by the blood, which
alters the activity of one or more specific target organs and is then destroyed by the liver
(i) explain what is meant by an endocrine gland, with reference to the islets of Langerhans in the