Get premium membership and access questions with answers, video lessons as well as revision papers.
1. Electrostatic precipitator – they are used in chimneys to reduce pollution by
attracting pollutants through electric ionization which then traps them by use of
plates (wire mesh). Finger printing and photocopying uses the same principle.
2. Spray painting– as air cruises above the paint droplets acquire similar charges
therefore spread out finely due to repulsion. Little paint is then used.
joseph rimiru answered the question on November 1, 2017 at 20:12
- Describe the process of charging by separation: having been supplied with two metal spheres with insulating stands, a polythene rod, woolen cloth, stand and thread.(Solved)
Describe the process of charging by separation: having been supplied with two metal spheres with insulating stands, a polythene rod, woolen cloth, stand and thread.
Date posted: November 1, 2017. Answers (1)
- State the charge acquired by a body using the contact method(Solved)
State the charge acquired by a body using the contact method
Date posted: November 1, 2017. Answers (1)
- You have been provided with polystyrene ball coated with aluminium paint, silk cloth, polythene rod, woolen cloth. Explain how one charges a conductor by contact...(Solved)
You have been provided with polystyrene ball coated with aluminium paint, silk cloth, polythene rod, woolen cloth. Explain how one charges a conductor by contact method.
Date posted: November 1, 2017. Answers (1)
- Explain what happens in the process of charging by induction.(Solved)
Explain what happens in the process of charging by induction.
Date posted: November 1, 2017. Answers (1)
- You have been provided with a polystyrene ball coated with aluminium, silk thread, glass rod, silk cloth, stand, polythene rod. Explain how you can charge...(Solved)
You have been provided with a polystyrene ball coated with aluminium, silk thread, glass rod, silk cloth, stand, polythene rod. Explain how you can charge a conductor by the induction method.
Date posted: November 1, 2017. Answers (1)
- Explain how a rise in the temperature of a gas causes rise in the pressure of the gas if the volume is kept constant(Solved)
Explain how a rise in the temperature of a gas causes rise in the pressure of the gas if the volume is kept constant
Date posted: November 1, 2017. Answers (1)
- Define friction and state the factors it depends on(Solved)
Define friction and state the factors it depends on
Date posted: November 1, 2017. Answers (1)
- Explain how convection takes place in a fluid(Solved)
Explain how convection takes place in a fluid
Date posted: November 1, 2017. Answers (1)
- State the conditions for total internal reflection to occur(Solved)
State the conditions for total internal reflection to occur
Date posted: November 1, 2017. Answers (1)
- State two factors affecting the velocity of sound in air(Solved)
State two factors affecting the velocity of sound in air
Date posted: November 1, 2017. Answers (1)
- State the charge of the electroscope(Solved)
State the charge of the electroscope
Date posted: November 1, 2017. Answers (1)
- State any two ways of increasing the size of an image formed by a fixed pinhole camera(Solved)
State any two ways of increasing the size of an image formed by a fixed pinhole camera
Date posted: November 1, 2017. Answers (1)
- (a) What is electrostatics? (b) Name two types of charges (c) Give the SI units of charge and other smaller units of charges and other smaller units...(Solved)
a. What is electrostatics?
b. Name two types of charges
c. Give the SI units of charge and other smaller units of charges and other smaller units of charge.
d. Explain how a body become positively or negatively charged
Date posted: October 31, 2017. Answers (1)
- A boy stands 400 cm from a large wall-mirror. He then walks slowly towards the mirror at a speed of 40 cm ...(Solved)
A boy stands 400 cm from a large wall-mirror. He then walks slowly towards the mirror at a speed of 40 cm per second. What is the distance between him and his image after 5 second?
Date posted: October 31, 2017. Answers (1)
- (a)What is main purpose of the translucent screen on the pinhole camera? (b)a lamp placed 9 cm high stand in...(Solved)
(a)What is main purpose of the translucent screen on the pinhole camera?
(b)a lamp placed 9 cm high stand in front of a pin hole camera at a distance of 27 cm. The camera screen is 12 cm from the pinhole. What is the height of the image on the screen?
Date posted: October 31, 2017. Answers (1)
- A pin hole camera of the length 20 cm forms an image 4 cm high of a woman standing 10 m in front of the camera. What is...(Solved)
A pin hole camera of the length 20 cm forms an image 4 cm high of a woman standing 10 m in front of the camera. What is the height of the woman?
Date posted: October 31, 2017. Answers (1)
- List two common application of plane mirrors (Solved)
List two common application of plane mirrors
Date posted: October 31, 2017. Answers (1)
- Define the term magnification(Solved)
Define the term magnification
Date posted: October 31, 2017. Answers (1)
- Define what is (a) Solar eclipse or eclipse of the moon (b) Annular eclipse of the sun (c) Lunar eclipse(Solved)
Define what is
a. Solar eclipse or eclipse of the moon
b. Annular eclipse of the sun
c. Lunar eclipse
Date posted: October 31, 2017. Answers (1)
- List four applications of convection in fluids.(Solved)
List four applications of convection in fluids.
Date posted: October 31, 2017. Answers (1)