Get premium membership and access questions with answers, video lessons as well as revision papers.
Postulate 1.electrons can revolve around the nucleus only in certain "allowed orbits" and while in this orbits they do not emit radiations. postulate 2.for circular motion,the allowed orbits are determined by the quantum condition that the angular momentum is in postulate 3.energy changes can only occur from one energy level to another and not between levels
lily nekesa answered the question on November 13, 2017 at 12:05
- Distinguish between spherical aberration and chromatic aberration(Solved)
Distinguish between spherical aberration and chromatic aberration
Date posted: November 13, 2017. Answers (1)
- Under which principle does the speed governor work?(Solved)
Under which principle does the speed governor work?
Date posted: November 13, 2017. Answers (1)
- State two advantages of the cloud chamber over a charged gold leaf electroscope when used
as detectors of radiations(Solved)
State two advantages of the cloud chamber over a charged gold leaf electroscope when used
as detectors of radiations
Date posted: November 12, 2017. Answers (1)
- State one advantage of a CRO as a voltmeter over other voltmeters.(Solved)
State one advantage of a CRO as a voltmeter over other voltmeters.
Date posted: November 12, 2017. Answers (1)
- What causes electrical resistance in conductors?(Solved)
What causes electrical resistance in conductors?
Date posted: November 12, 2017. Answers (1)
- State the advantage of generating an Ac supply rather than DC voltage supply in a power station(Solved)
State the advantage of generating an Ac supply rather than DC voltage supply in a power station
Date posted: November 12, 2017. Answers (1)
- State one difference between a chemical reaction and radioactivity.(Solved)
State one difference between a chemical reaction and radioactivity.
Date posted: November 12, 2017. Answers (1)
- State the conditions necessary for a wave incident on a slit to be diffracted(Solved)
State the conditions necessary for a wave incident on a slit to be diffracted
Date posted: November 12, 2017. Answers (1)
- (a) State one similarity and one difference between a concave lens and a convex mirror (b) A lens forms a focused image on a screen...(Solved)
(a) State one similarity and one difference between a concave lens and a convex mirror
(b) A lens forms a focused image on a screen when the distance between the object and the lens is 100 cm. the size of the image is twice that of the object.
(i) What kind of lens was used? Give a reason
(ii) Determine the distance of the image from the lens
(iii) Determine the power of the lens
Date posted: November 12, 2017. Answers (1)
- Differentiate between Faradays law of electromagnetic induction and Lenz law.(Solved)
Differentiate between Faradays law of electromagnetic induction and Lenz law.
Date posted: November 12, 2017. Answers (1)
- Describe how you would charge a gold leaf electroscope by induction method(Solved)
Describe how you would charge a gold leaf electroscope by induction method
Date posted: November 12, 2017. Answers (1)
- Sauce pans have a plastic or wooden handles. It is observed that in the morning the pan feels colder than the wooden handle.
Explain the...(Solved)
Sauce pans have a plastic or wooden handles. It is observed that in the morning the pan feels colder than the wooden handle.
Explain the difference in this observation
Date posted: November 12, 2017. Answers (1)
- Trees planted along a busy road are observed to lean towards the road as they grow. Explain this observation(Solved)
Trees planted along a busy road are observed to lean towards the road as they grow. Explain this observation.
Date posted: November 12, 2017. Answers (1)
- Explain why copper is a better conductor of heat than iron(Solved)
Explain why copper is a better conductor of heat than iron
Date posted: November 12, 2017. Answers (1)
- Explain the reason why a dropping dust particle in a still room does not trace a straight vertical path(Solved)
Explain the reason why a dropping dust particle in a still room does not trace a straight vertical path
Date posted: November 12, 2017. Answers (1)
- Explain briefly how a p-type semiconductor is made(Solved)
Explain briefly how a p-type semiconductor is made
Date posted: November 12, 2017. Answers (1)
- What is Physics?(Solved)
What is Physics?
Date posted: November 10, 2017. Answers (1)
- A negatively charged polythene rod is placed on a pan of electric balance. State and explain what happens to the balance reading if a positively...(Solved)
A negatively charged polythene rod is placed on a pan of electric balance. State and explain what happens to the balance reading if a positively charged glass rod is brought closer to the polythene rod.
Date posted: November 8, 2017. Answers (1)
- State three factors that affect the proportionality constant of a helical spring(Solved)
State three factors that affect the proportionality constant of a helical spring
Date posted: November 8, 2017. Answers (1)
- State two characteristics of perfectly inelastic collisions(Solved)
State two characteristics of perfectly inelastic collisions
Date posted: November 8, 2017. Answers (1)