SQA Higher Physics Area 3 Electricity overview quiz quiz

The root-mean-square value

The average value

The frequency

The peak value

V_peak equals the square root of two times V_rms

V_peak equals V_rms, since the two values are always the same

V_peak equals two times V_rms for any sinusoidal supply voltage

V_peak equals V_rms divided by the square root of two each time

From the height of the trace read off the screen directly

From the period of one cycle, using f equals one over T

From the volts-per-division setting on the oscilloscope dial

By dividing the peak voltage by the square root of two each time

8 ohms

4 ohms

2 ohms

16 ohms

P equals IV

P equals V squared over R

P equals V over I

P equals I squared R

V_s times R1 over (R1 plus R2)

V_s times R2 over (R1 plus R2)

V_s times (R1 plus R2) over R1

V_s times R1 times R2

Because the emf of the source itself decreases as the current rises

Because the lost volts (Ir) across the internal resistance increase

Because the external resistance in the circuit steadily increases

Because the frequency of the supply rises with the current

The internal resistance

The lost volts

The emf of the source

The external resistance

E equals QV, the full charge times voltage

E equals CV, capacitance times voltage

E equals Q divided by V

E equals one half QV

Starts at a maximum and falls towards zero

Stays completely constant throughout the charging

Starts at zero and rises steadily to a maximum value

Reverses its direction repeatedly while charging up

Positively charged holes

Free electrons

Protons in the nucleus

Neutrons in the lattice

When reverse biased, with the n-side to the positive terminal

Only when no voltage at all is applied across the junction

When forward biased, with the p-side to the positive terminal

In both directions equally, just like an ordinary resistor