Electricity Part 4: Resistivity

A Level results day has recently come around, GCSE results day is next week.

Did you get the results you wanted? Are you looking at resits? Do you need help with your studies? Feel free…

Easter seems to have rolled around faster than ever this year. While the Covid situation may still be subject to change, it seems highly likely that A Level and GCSE exams will go ahead this…

With Omicron cases on the rise, it seems that more school closures will be likely from January. I am available during weekdays as well as evenings and weekends to help students who are learning at…

Once again the UK school summer holidays are approaching. This comes after 15 months of schooling disrupted by multiple COVID-related lockdowns. Schools have worked extremely hard to provide online tuition to the highest possible standard…

As recorded cases of COVID continue to rise, it is looking increasingly likely that the UK is heading for a second period of lockdown.

I am available for online tutoring weekdays as well as evenings…

A brief introduction to a topic that students often find tricky.

In the planetary or Rutherford model of the atom, negatively-charged electrons orbit the positive nucleus like planets in a solar system. However, under this…

In part 2 we discussed Ohm’s Law where current is proportional to p.d. provided resistance is constant.

I-V Characteristics show how current varies with p.d. for different components: those that obey Ohm’s Law (i.e. resistance…

In part 1 we talked about the resistance of a component.

The resistance of a component is the ratio of the p.d. (voltage) across it to the current flowing through it. Materials with zero resistance…

Electricity is a topic which seems to confuse a lot of students. Perhaps because electric current cannot be seen so a lot has to be taken ‘on trust’, perhaps because the topic lends itself to…

A few words on my experience of online tutoring during the COVID-19 crisis school closure. I have had extensive experience tutoring maths and science online before the school closure but my bread and butter was…

Many students are confused by Potential Dividers but this need not be the case.

A potential divider is a circuit which uses two resistors or a rheostat (variable resister) with a moveable contact. A potential…

Did you know Thomas McKennan Tutors offer more than just maths and physics tuition?

We have a team of experienced tutors who can offer one-to-one tuition in any subject at any level. Whether you need…

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Unless you've been hiding under a rock for most of the last year, you'll know…

Part 2: Compound Uncertainties.

Where a result is calculated using a formula, every measurement used in the calculation contributes to the uncertainty of the result. This is what we mean by compound uncertainties.

The method…

This is a topic which seems to confuse a lot of students but it needn’t be so. The word error suggests a mistake in a result but this is not the case: the word uncertainty…

Newton’s Third Law

Every action has an equal and opposite reaction.

Everyone knows this catchphrase but Newton’s Third Law still causes much misunderstanding.

The first two laws concern the balance or imbalance of forces acting…

Newton’s laws of motion

Newton’s laws of motion are the basis for our understanding of the mechanical world. While students may or may not know them by name, they underpin most of the mechanics in…

You will have noticed that in the sixth-form, you need to take more personal responsibility for organising your notes, your work and your timetable. For some people, this is easier than for others!

I was…

In my last post, I talked about some of the problems A Level Physics students encounter in mass-energy (E=mc²) calculations. In passing, I mentioned use of unfamiliar units during the calculations. This is a guide…

E = mc² is the most famous equation of all time. It has become an icon of science, of knowledge and of learning, way beyond its origins in Einstein’s work and its applications in nuclear…

In the beginning it was simple. We lived on a perfect plane laid out under the heavens or, later in our history, a round orb at the centre of the universe.

We discovered other worlds…

We’ve all grown up learning that there were nine planets in the solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto.

Perhaps you even learned sayings like Many Visitors Eat Mouldy Jam Sandwiches…

A brief reflection on the professional and personal qualities that make for excellence in education.

What makes a good teacher?

• Thorough subject knowledge.
• Enthusiasm for subject.
• Ability to communicate ideas clearly.
• Empathy with students.
• Ability…

The story of the Universe, if considered chronologically from its birth to possible fate is an often confusing one which starts and ends with complex, unfamiliar physics, abstract thinking and the sorts of questions which…

Students are often unsure of how to answer questions about practical work. This is a brief guide to the main points that should be covered in order to adequately describe the procedure to be followed.…