Module 4 Series and Parallel Circuits

Question 1

Name these symbols

Answer 1

Open switch and closed switch

Question 2

Name this symbol

Answer 2

Cell

Question 3

Name this symbol

Answer 3

Battery

Question 4

Name this symbol

Answer 4

Diode

Question 5

Name this symbol

Answer 5

Resistor (or Ohmic conductor)

Question 6

Symbol for a variable resistor

Answer 6

Question 7

Name this symbol

Answer 7

Thermistor

Question 8

Name this symbol

Answer 8

LDR (light dependent resistor)

Question 9

Symbol for LED (light emitting diode)

Answer 9

Question 10

What is this?

Answer 10

symbol for a capacitor

Question 11

How is current shared in a series circuit?

Answer 11

current is same at every point in the circuit (at a particular time)

this also applies to one branch of a parallel circuit

Question 12

How is current shared in a parallel circuit?

Answer 12

current is shared between the branches depending on the resistance

(R inversely proportional to I)

Question 13

How is voltage shared in a series circuit?

Answer 13

voltage of power source is shared between components used depending on their resistance (Kirchhoff’s 2nd law)

applies to voltage on one branch of a parallel circuit

Question 14

How is voltage shared in a parallel circuit?

Answer 14

voltage is same across each branch of the circuit

Question 15

How is the power of a component in a series circuit related to its resistance?

Answer 15

P=I^2R - I is the same at a given point in time so P∝R, higher the resistance the higher the power (in bulbs the brighter the bulb)

Question 16

How is the power of a component in a parallel circuit related to its resistance?

Answer 16

P=V^2/R, V is the same across each branch so we can say that P is proportional to 1/R

Question 17

What is the total resistance of a series circuit?

Answer 17

the sum of individual resistances of all components

Question 18

Why does a voltmeter need to have very high resistance?

Answer 18

to minimise change in current over the component being measured. V=IR, V is same R greater so I must be smaller

Question 19

Why does an ammeter need to have a very low resistance?

Answer 19

so current and voltage remains unchanged. V is shared between all components in series according to resistance, V=IR, if R is small and I is same through all components at any point in time V will be small

Question 20

What is the total resistance of a parallel circuit?

Answer 20

Total R = (1/R1 + 1/r2 + ….)^-1