Basicrental
-
(base units Micrometer
7 SI Base units A tool used for widths thickness
measuring
-
small or
-
,
diameters. (e g
. the diameter of a copper
.
wire)
-
Resolution : 0 .
0 Imm
Scales- The main scale : this is the
It
-
on sleeve
I sometimes called the barrel
he thimble scale : this is a rotating scale on
How to read a micrometer the thimble.
Entire force) : is defined as the
energy
transferred from chemical energy
↳ work per unit
charge (E W/Q) =
done to charge carriers when
they gain energy
potential difference : is defined the energy transferred from electrical to other
as
energy
forms , unit charge V = w / Q.
per ,
C. m.t and
in series
parallel
-
Series · Etotal =
E .
+ Ent EstEnt ....
-
Parallel : Etotal =
E .
=
Ec =
Es =
Ex =...
(the amount of charge flowing in the circuit doesn't change
by adding cells in
parallel ,
but
the number of paths the charges can take does
,Internal Resistance : The resistance that all power supplies have between their terminals
=> Not all of the energy transferred to the charge carriers is available to the circuit ,
as some
is transferred to the internal resistance of the cell.
Lost volts : p d .
. across the internal resistor.
E =
V+ In
u
↳ Lost volts
To determine internal resistance
& Connect the cell with internal resistance r in series to an ammeter
and a variable resistor .
& Connect a voltmeter in parallel around the cell .
& Vary the resistance of the variable resistor and record the V and I readings.
⑪ The equation E =
V + Ir is rearranged to V =
E-Ir .
⑤ Plot graph a of terminal p .
d (v) against current (1) and draw a line of best fit.
& They intercept of the graph will be the e m
.
. f of the cell and the negative gradient will be
the internal resistance of the cell
d (v)
p .
.
X
E
-
ive slope =
-r
O
7 Curren + / A
NTC Thermistor
=
Negative temperature coefficient
=> As the temperature of the material increases ,
the resistance of the material decreases
x[(A)
TT = RJ
The thermistor is non-ohmic component
R(c)
X
> p d(U)
.
°
> T( C
, Potential divider
Kirchoff's second Law : the current in a series circuit is constant and the p d. .
splits in a ratio
proportion to the resistance of each component
.
Vin
---
=
Ro R .
** von = R
* e . m . f
< Vout ;
Investigating potential divider
thermistor
using a
&
=
Vin
& place the thermistor in a beaker of ice water.
---
R2 R,
VI
I & Measure the
the voltage
initial
across
temperature
the thermistor.
of the water and record
& Heat the beaker
using a bunsen burner I make sure the water is
v
well-stirred) ,
and record the temperature andout at
regular intervals over a suitable
°
range (e g
. at . 52 intervals over a
range of 0-100 ) .
# Plot a
graph of Vout against the temperature from results.
your
& From the
graph ,
you should see that as the temperature of the water increases ,
Vout decreases.
Using LDR (light dependent resistor
Vin ① Set
---
up the Circuit with LDR and resistor R in series ·
I
& Record the value of the light intensity using the digital
VI
4t
light sensor in a
completely dark room.
& Record the voltage the resistor for this
across
light intensity
V
-
from the voltmeter.
⑪ Using the lamp with a dimmer switch. increase the light intensity slightly and record
the new value recorded by the sensor.
& Record the voltage across the resistor again with this new light intensity
.
& Repeat this process until the light intensity from the lamp cannot be increased further.
any
-
(base units Micrometer
7 SI Base units A tool used for widths thickness
measuring
-
small or
-
,
diameters. (e g
. the diameter of a copper
.
wire)
-
Resolution : 0 .
0 Imm
Scales- The main scale : this is the
It
-
on sleeve
I sometimes called the barrel
he thimble scale : this is a rotating scale on
How to read a micrometer the thimble.
Entire force) : is defined as the
energy
transferred from chemical energy
↳ work per unit
charge (E W/Q) =
done to charge carriers when
they gain energy
potential difference : is defined the energy transferred from electrical to other
as
energy
forms , unit charge V = w / Q.
per ,
C. m.t and
in series
parallel
-
Series · Etotal =
E .
+ Ent EstEnt ....
-
Parallel : Etotal =
E .
=
Ec =
Es =
Ex =...
(the amount of charge flowing in the circuit doesn't change
by adding cells in
parallel ,
but
the number of paths the charges can take does
,Internal Resistance : The resistance that all power supplies have between their terminals
=> Not all of the energy transferred to the charge carriers is available to the circuit ,
as some
is transferred to the internal resistance of the cell.
Lost volts : p d .
. across the internal resistor.
E =
V+ In
u
↳ Lost volts
To determine internal resistance
& Connect the cell with internal resistance r in series to an ammeter
and a variable resistor .
& Connect a voltmeter in parallel around the cell .
& Vary the resistance of the variable resistor and record the V and I readings.
⑪ The equation E =
V + Ir is rearranged to V =
E-Ir .
⑤ Plot graph a of terminal p .
d (v) against current (1) and draw a line of best fit.
& They intercept of the graph will be the e m
.
. f of the cell and the negative gradient will be
the internal resistance of the cell
d (v)
p .
.
X
E
-
ive slope =
-r
O
7 Curren + / A
NTC Thermistor
=
Negative temperature coefficient
=> As the temperature of the material increases ,
the resistance of the material decreases
x[(A)
TT = RJ
The thermistor is non-ohmic component
R(c)
X
> p d(U)
.
°
> T( C
, Potential divider
Kirchoff's second Law : the current in a series circuit is constant and the p d. .
splits in a ratio
proportion to the resistance of each component
.
Vin
---
=
Ro R .
** von = R
* e . m . f
< Vout ;
Investigating potential divider
thermistor
using a
&
=
Vin
& place the thermistor in a beaker of ice water.
---
R2 R,
VI
I & Measure the
the voltage
initial
across
temperature
the thermistor.
of the water and record
& Heat the beaker
using a bunsen burner I make sure the water is
v
well-stirred) ,
and record the temperature andout at
regular intervals over a suitable
°
range (e g
. at . 52 intervals over a
range of 0-100 ) .
# Plot a
graph of Vout against the temperature from results.
your
& From the
graph ,
you should see that as the temperature of the water increases ,
Vout decreases.
Using LDR (light dependent resistor
Vin ① Set
---
up the Circuit with LDR and resistor R in series ·
I
& Record the value of the light intensity using the digital
VI
4t
light sensor in a
completely dark room.
& Record the voltage the resistor for this
across
light intensity
V
-
from the voltmeter.
⑪ Using the lamp with a dimmer switch. increase the light intensity slightly and record
the new value recorded by the sensor.
& Record the voltage across the resistor again with this new light intensity
.
& Repeat this process until the light intensity from the lamp cannot be increased further.
any
