electric circuits

Question 1

characteristics of seriest circuit current

Answer 1

have the same current everywhere

Question 2

characteristics of series circuit ressitance and p.d

Answer 2

and all the p.d adds up
resistance= r1 + r2

Question 3

parralel circuits p.d

Answer 3

p.d is the same

Question 4

parralell circuits current

Answer 4

current adds up

Question 5

resistors in parralell circuits

Answer 5

R= (r1 x R2)/(R1+R2)

Question 6

what are th advantages of parralell circuits

Answer 6

• all the components can be switched on and of independently
• if one lamp breaks, others still work fine
• components in parrallel recieve the p.d they where desighned for

Question 7

the total resistance of a parralel ccircuit is less or more than any resistor in that cicuit

Answer 7

less

Question 8

the resistance in parallel is alwars less or more than hat in series

Answer 8

less

Question 9

is the current from cell greater or smaller in parallel

Answer 9

greater

Question 10

what is the potential divider

Answer 10

it can be 2 resistors in series or a variable resistor with 3 connections. by adjusting the variable resistor which alters the ratio of 2 resistors, we can control the output voltage
used in eg: dimmer switches, sound volume etc
Vout= R1/R1+R2 x Vin

Question 11

what are transducers

Answer 11

device that changes forms of energy

Question 12

what is a thermistor

Answer 12

a thermistor, LDR, microphone are all sensors that convert a form of energy into electricity

Question 13

what is a direct current

Answer 13

it is made by cells by d.c generators- direct current flows in one direction and has constant size when flowing through a resistor of constant value

Question 14

what is an alternating current?

Answer 14

alternating currents are made by a ac generator. alternating current repeatedly changes both size and direction. most electricity and power transmissions are ac.

Question 15

formula of frequency

Answer 15

f= 1/T

Question 16

what is the diode

Answer 16

the diode is a semi conductor that allows current to pass in one direction only

Question 17

rectification

Answer 17

converting na.c to d.c- only positive current can be seen in the graph

Question 18

how does the p.d across an electrical conducter relate to its resistance for constant current

Answer 18

the p.d. across an electrical conductor
increases as its resistance increases for a constant
current

Question 19

the equation for two resistors used
as a potential divider

Answer 19

R1/R2
= V1/V2