PHYSICS-UNIT 2 ELECTRICITY

use the equations 𝑄 = 𝐼𝑡 𝑎𝑛𝑑 𝑄 = ±𝑁𝑒 (N refers to number of charges) to solve problems;

1.2. define the ‘Coulomb’;

1.3. define potential difference and the ‘Volt’;

1.4. use the equation V = W/Q to solve problems;

1.5. use the equation V = IR to solve problems;

use the equations P = IV, P = I2R, P = V2 /R to solve problems;

1.7. use the formula ρL R= A to determine resistivity

derive the equation I = nqvA for charges moving in a metal (n = charge density); and

1.11. use the equation I = nqvA for charges moving in a metal (n = charge density).

compare Ohmic and nonOhmic devices using an IV graph;

sketch the variation of resistance with temperature for a thermistor with negative temperature coefficient;

solve problems involving terminal p.d. and external load, given that sources of e.m.f. possess internal resistance;

Draw and interpret circuit diagrams

Apply kirchhoff’s laws

derive the formula for the effective resistance of two or more resistors in series or parallel;

use the formula for two or more resistors in series or parallel;

explain the difference between electrical conductors and insulators; An electron model should be used in the explanation.

use Coulomb’s Law: 𝐹 = 𝑄1𝑄2 4𝜋𝜀0𝑟 2 to calculate the force between charges in free space or air to solve problems;

use 𝐸 = 𝑄 4𝜋𝜀0𝑟 2 for the field strength due to a point charge

calculate the field strength of the uniform field between charged parallel plates

calculate the force on a charged particle in a uniform electric field;

describe the effect of a uniform electric field on the motion of charged particles;

solve numerical problems involving the motion of charged particles in a uniform electric field;

compare the motion of charged particles in a uniform electric field to that of a projectile in a gravitational field; 3.9. use the fact that the field strength at a point is numerically equal to the potential gradient at that point;

use the equation 𝑉 = 𝑄 4𝜋𝜀0𝑟 for the potential due to a point charge; and,

find the potential at a point due to several charges.

define capacitance; 4.2. use the equation Q C= V to solve problems; 4.3. use the formula εA C= d ; 𝐶 = 𝜀𝑟𝜀𝑜𝐴 𝑑 εr – relative permittivity or dielectric constant ε0 – permittivity of free space.

derive formulae for capacitors in parallel and series to solve problems;

use formulae for capacitors in parallel and series to solve problems;

use the formulae for energy stored in a capacitor as 𝑊 = 𝐶𝑉2 2 , 𝑊 = 𝑄𝑉 2 𝑎𝑛𝑑 𝑊 = 𝑄 2 2𝐶 to solve problems;

Recall the equations for capacitor charge and discharge (RC is the time constant and measured in seconds)

use the equations for capacitor charge and discharge;

and, 4.9. sketch graphs illustrating the charge and discharge of a capacitor.