Get premium membership and access questions with answers, video lessons as well as revision papers.
Fossil fuels
Fossil fuels occur naturally in the earth and are the remains of living organisms from the geological past. They include coal, oil and natural gas, which generate electricity when they burn in large electric power plants.
Nuclear power
Nuclear power is a nonrenewable energy source that uses radioactive materials as part of the process of heating water to generate electricity. The process generates zero atmospheric emissions, as stated by the National Academy of Sciences.
Renewable energy
Renewable energy sources are naturally replenished and include biomass, hydro, geothermal, solar and wind. Some of these renewable sources are intermittent, such as wind, which can create complications when using them to generate electricity on a large scale.
chrispohmomanyi answered the question on October 10, 2017 at 04:05
- An electrical heater rated 240 v, 2000 w is to be connected to a 240 v mains supply through a fuse of 9.0 A. ...(Solved)
An electrical heater rated 240 v, 2000 w is to be connected to a 240 v mains supply through a fuse of 9.0 A. Will the fuse be suitable? Give a reason.
Date posted: October 9, 2017. Answers (1)
- A n electric bulb rated, 4W is operating on a 240 v mains. Determine the filament’s resistance.(Solved)
A n electric bulb rated, 4W is operating on a 240 v mains. Determine the filament’s resistance.
Date posted: October 9, 2017. Answers (1)
- A capacitor is connected to the distributor in some petrol engines which use spark plugs. What is its function?(Solved)
A capacitor is connected to the distributor in some petrol engines which use spark plugs. What is its function?
Date posted: October 9, 2017. Answers (1)
- What does polarization show in light?(Solved)
What does polarization show in light?
Date posted: October 9, 2017. Answers (1)
- State two conditions under which Ohm’s law is obeyed in a given metal.(Solved)
State two conditions under which Ohm’s law is obeyed in a given metal.
Date posted: October 9, 2017. Answers (1)
- If the p.d. of 0.75 v is applied at the end of a wire of length 1.0 m long with a cross-sectional area of 1.6...(Solved)
If the p.d. of 0.75 v is applied at the end of a wire of length 1.0 m long with a cross-sectional area of 1.6 x 10^-4 m^2 and a current of 1.4 A flow through it. Calculate its resistivity.
Date posted: October 9, 2017. Answers (1)
- Given that the resistance of a wire is 1 ohm. Its resistivity is 5.0 x 10^-7 ohms and its cross- sectional area is 4.0...(Solved)
Given that the resistance of a wire is 1 ohm. Its resistivity is 5.0 x10^-7 ohms and its cross- sectional area is 4.0 x 10 -6 m^2. Find its length.
Date posted: October 9, 2017. Answers (1)
- In a certain building during construction, a crane lifted a load of 4000 kg through a vertical distance of 6.0m in 12 seconds.
Determine the:
i. Work done
ii. Power...(Solved)
In a certain building during construction, a crane lifted a load of 4000 kg through a vertical distance of 6.0m in 12 seconds.
Determine the:
i. Work done
ii. Power developed by the crane
iii. Efficiency of the crane if it is rated 25 kw
Date posted: October 9, 2017. Answers (1)
- A sliding body on an inclined plane is affected by some factors. Name two factors.(Solved)
A sliding body on an inclined plane is affected by some factors. Name two factors.
Date posted: October 9, 2017. Answers (1)
- A horizontal force of 24 N is applied on a metallic block of mass 5 kg placed on a horizontal surface. The block was accelerated...(Solved)
A horizontal force of 24 N is applied on a metallic block of mass 5kg placed on a horizontal surface. The block was accelerated to 10 m/s^2. Determine the frictional force between the block and the surface.
Date posted: October 9, 2017. Answers (1)
- A wheelbarrow of mass 50 kg was pushed along a horizontal path by a horizontal force of 10 N and moves with a constant velocity....(Solved)
A wheelbarrow of mass 50 kg was pushed along a horizontal path by a horizontal force of 10 N and moves with a constant velocity. The force was then increased to 18N. Determine :
a. The resistance to the motion of the wheelbarrow
b. The acceleration of the wheelbarrow.
Date posted: October 9, 2017. Answers (1)
- State any three ways in which the induced emf in the generator can be increased.(Solved)
State any three ways in which the induced emf in the generator can be increased.
Date posted: October 9, 2017. Answers (1)
- State types of transformers(Solved)
State types of transformers
Date posted: October 9, 2017. Answers (1)
- State three factors that affect electrical energy.(Solved)
State three factors that affect electrical energy.
Date posted: October 9, 2017. Answers (1)
- State the factors affecting resistance of a conductor(Solved)
State the factors affecting resistance of a conductor.
Date posted: October 9, 2017. Answers (1)
- State three disadvantages of lead acid accumulators(Solved)
State three disadvantages of lead acid accumulators
Date posted: October 9, 2017. Answers (1)
- State two disadvantages of simple cell.(Solved)
State two disadvantages of simple cell.
Date posted: October 9, 2017. Answers (1)
- State two types of cells.(Solved)
State two types of cells.
Date posted: October 9, 2017. Answers (1)
- What is a capacitor?(Solved)
What is a capacitor?
Date posted: October 9, 2017. Answers (1)
- Define Surface charge density.(Solved)
Define Surface charge density.
Date posted: October 9, 2017. Answers (1)