Entire Phsyics

What is the value of the prefix T (tera)

10¹²

What is the value of the prefix G (giga)

10⁹

What is the value of the prefix M (mega)

10⁶

What is the value of the prefix k (kilo)

10³

What is the value of the prefix d (deci)

10⁻¹

What is the value of the prefix c (centi)

10⁻²

What is the value of the prefix m (milli)

10⁻³

What is the value of the prefix μ (micro)

10⁻⁶

What is the value of the prefix n (nano)

10⁻⁹

What is the value of the prefix p (pico)

10⁻¹²

What six base units of the SI system are used in A Level Physics?

metre, kilogram, second, Ampere, Kelvin, Mole

What six base quantities of the SI system are used in A Level Physics?

length, mass, time, electric current, absolute temperature, amount of substance.

What is the base unit of mass?

kg

What is the base unit of length?

m

What is the base unit of time?

s

What is the base unit of current?

A

What is the base unit of absolute temperature?

K

What is the Unit of potential difference?

V

What are the Units of density?

kgm⁻³

What is the SI unit of energy?

J

What is the SI unit of power?

W

What is the SI unit of charge?

C

What units are equivalent to the volt?

JC⁻¹

What base units are equivalent to the Newton?

kgms⁻²

What base units are equivalent to the Joule?

kgm²s⁻²

What units are equivalent to the Pascal?

Nm⁻²

What are the units of momentum?

kgms⁻¹

What are the units of resistivity?

Ωm

What units are equivalent to a Watt?

Js⁻¹

What are the units of angular velocity (ω)?

rad. s⁻¹

What is 1m² in mm²?

10⁶mm²

What is 1m³ in cm³?

10⁶cm³

What is 1km² in m²?

1x10⁶m²

What is 1cm³ in mm³?

10³mm³

There are 10²⁴ free charge carriers per m³ of a material. How many are there per mm³?

10¹⁵

10⁶ particles strike each mm² of a surface per second. How many strike 1m² of the surface per second?

10¹²

If there is 1 particle per mm³, how many are there per m³?

10⁹

Water has a density of 1000kgm⁻³. What is this in kgcm⁻³?

10⁻³

Water has a density of 1000kgm⁻³. What is this in gcm⁻³?

1

What is a control variable?

Something that must be kept constant to prevent it affecting the dependent variable

What is meant by the repeatability of results?

Similar results would be obtained from repeats of the same measurement from the same experimental set up.

What is meant by the reproducibility of results

Similar results would be obtained from repeats by different people with different equipment.

How can you ensure a metre rule is held vertically?

Use a plumb line, set square or spirit level

How do you avoid parallax error?

Ensure eye, object and scale are all in line with each other OR ensure object and scale are directly adjacent to each other

What is meant by the term random error?

Errors that cause the measurement to vary in unpredictable ways.

What is a systematic error?

An error that causes the measurements to differ from the true value by a consistent amount.

What is a zero error?

An error that occurs due to the measuring instrument reading a non-zero reading when the measured quantity is zero.

What is meant by the accuracy of a result?

How close a measurement is to the 'true' or accepted value

What is meant by the precision of results?

How close repeated measurements are to each other.

What is meant by the resolution of a measuring instrument?

The smallest change in quantity that can be measured.

What determines the resolution when using a multimeter?

The scale selected.

What is the resolution of a metre rule?

1mm

What is the resolution of vernier calipers?

0.1mm

What is the resolution of a micrometer

0.01mm

How do you find the absolute uncertainty from repeated readings?

± ½ the range of the repeats

How do you estimate uncertainty when repeated results are identical?

± ½ the resolution of the instrument

How do you calculate percentage uncertainty?

(Absolute uncertainty ÷ 'calculated OR measured' value) × 100

What do you do to the uncertainties when quantities are added or subtracted?

The absolute uncertainties are added together

What do you do to the uncertainties when quantities are multiplied or divided?

The percentage uncertainties are added together

What do you do to the uncertainties when a quantity is raised to a power?

The percentage uncertainty is multiplied by that power

How do you find the uncertainty in a gradient?

± (gradient of the line of best fit − gradient of the line of worst fit)

What is a line of worst fit?

The steepest or shallowest line that passes through the error bars.

What are error bars?

Lines to show the range of the absolute uncertainty of each data point on a graph

How do you find uncertainty in a y-intercept?

± (y-intercept of the line of best fit − y-intercept of the line of worst fit)

What is a charge carrier?

A charged particle capable of transferring electric current.

What do we mean when we say charge is quantised?

It can only take certain values (always ne)

If n electrons are removed from a neutral object what is its charge?

ne

What is an electrolyte?

A liquid containing charged ions.

What is a metallic conductor?

A material comprising a lattice of positive ions and delocalised electrons that carry electrical current

Which direction does conventional current flow?

From positive to negative.

Which direction do electrons flow in a circuit?

From negative to positive.

What is an ion?

A non-neutral atom or molecule.

What is a cation?

A positively charged ion

What is an anion?

A negatively charged ion.

What is an anode?

A positive electrode.

What is a cathode?

A negative electrode.

How is an ammeter connected?

In series

What is the resistance of an ideal ammeter?

Zero.

State Kirchoff's first law.

At any point in a circuit the sum of the currents entering that point is equal to sum of the currents leaving.

What is n in the equation I = nAve and what are its units?

Number density of free charge carriers m⁻³

What is A in the equation I = nAve?

Cross-sectional area of the conductor.

What is e in the equation I = nAve?

The elementary charge (1.6x10⁻¹⁹C)

What is v in the equation I = nAve?

The drift velocity of the charge carriers.

What is a conductor?

A material with a large number density of charge carriers ~10²⁸m⁻³

What is an insulator?

A material with a low number density of charge carriers.

What is a semiconductor?

A material with an intermediate number density of charge carriers ~10¹⁷m⁻³

What is potential difference?

The work done per unit charge between two points

What is the SI unit for potential difference?

Volt (V)

What units are equivalent to the volt?

Joules per Coulomb (JC⁻¹ )

What is EMF (Electromotive force)?

The work done per unit charge supplied to the charge carriers

How is a voltmeter connected?

In parallel.

What is the resistance of an ideal voltmeter?

Infinite.

What is thermionic emission?

The emission of electrons from the surface of a heated metal.

What is the work done on an electron when it passes through a p.d. of V volts?

eV where e is the charge on the electron.

What is Ohm's Law?

For a metallic conductor at constant temperature the p.d. is proportional to current.

What is electrical resistance?

The opposition of an object to a flow of current through it.

How is resistance calculated?

V/I

What units are equivalent to an Ohm?

VA⁻¹

Why does resistance increases with temperature?

The amplitude of lattice ion vibrations increases causing more frequent collisions between electrons and lattice ions, leading to the electrons doing more work as they move through the wire.

Why does current flow lead to heating in components?

Electrons collide with the lattice ions and transfer some of their kinetic energy to the lattice ion's vibrations.