General Science 11: Electrical Safety and Efficiency

Comprehensive practice questions covering electrical transformations, hazards, safety devices, energy calculations, and conservation strategies based on General Science 11 notes.

What are the common energy transformations for an electric fan and a washing machine?

Electrical (\rightarrow) Mechanical

How does energy transform in a light bulb?

Electrical (\rightarrow) Light + Heat

What is the energy transformation in a rice cooker?

Electrical (\rightarrow) Heat

What energy transformations occur in a television?

Electrical (\rightarrow) Light + Sound

What is the definition of electrical overloading?

It occurs when too many devices draw current from one outlet, extension cord, or circuit.

What are the warning signs of damaged insulation?

Exposed wires, loose plugs, cracked cords, or visible melting.

Why is water a hazard in electrical conditions?

Water containing dissolved minerals can conduct electric current, and wet skin lowers electrical resistance.

What should you do if you encounter faulty wiring sparked by loose or damaged connections?

Stop using the affected outlet and report it to a qualified electrician or responsible adult.

What is the distinction between electric shock and electrocution?

Electric shock is the passage of current through the human body; electrocution is death specifically caused by electric shock.

List the factors that affect the severity of an electric shock.

The amount of current, length of time in contact, path of the current, condition of the skin (wet or dry), and voltage of the source.

What is the first rule to remember during an electrical emergency involving a victim?

Do NOT touch a person who is still in contact with an electrical source.

What is the function of a fuse?

A thin metal element that melts when excessive current flows, thereby breaking the circuit.

How does a circuit breaker work differently than a fuse?

It automatically interrupts a circuit when excessive current is detected and can usually be reset after the fault is corrected, whereas a fuse must be replaced.

What is the purpose of grounding in a circuit?

It provides an alternative path for fault current to flow toward the ground, helping to reduce the risk of electric shock.

What are three safe practices for using extension cords?

Use them within their rated capacity, avoid connecting one to another (daisy-chaining), and treat them as temporary connections rather than permanent wiring.

What is the formula for calculating electrical efficiency?

$$\text{Efficiency} = ( \frac{\text{Useful Energy Output}}{\text{Total Energy Input}} ) \times 100\%$$

In what unit is electrical power measured?

Watts ($W$)

What is the formula for calculating household electrical energy consumption?

$$\text{Electrical Energy (kWh)} = \text{Power (kW)} \times \text{Time (h)}$$

If a $100\,W$ television is used for $5$ hours, how many kilowatt-hours ($kWh$) are consumed?

$100\,W = 0.1\,kW$; therefore, $0.1\,kW \times 5\,h = 0.5\,kWh$

What are three ways to save electricity regarding air conditioning?

Keep doors and windows closed while operating, clean filters regularly, and avoid cooling empty rooms.

How does Inverter Technology improve efficiency in appliances?

It allows appliances like air conditioners and refrigerators to adjust their operating speed based on demand.

What is the function of Energy Labels on appliances?

They help consumers compare the energy consumption and efficiency of different appliances before making a purchase.

Define the term 'Insulator' in the context of electricity.

A material that resists the flow of electric current.