Download 7TH CLASSES PHYSICS DAILY PLAN

10TH CLASSES
PHYSICS
DATE:…………………
DAILY PLAN
b) Parallel combination:
SUBJECT: Combination of resistors:
AIM: students have to know the measurement of
current and voltage of a combination of resistors
DURATION: 80 min
REAL LIFE: functions of resistors in an electric
circuit
PRESENTATION:
The Measurement of Potential Difference,
Current and Resistance:
In a circuit, a potential difference can be measured
by using an instrument called Voltmeter. A voltmeter
is connected so that it must be placed in parallel with
the resister. An ideal voltmeter has infinite resistance
so that no current will pass through it.
To measure the current, the instrument is called
ammeter. An ammeter is constructed so that it must
be placed in series with the current that it is to
measure. Ideally, an ammeter should have zero
resistance so as not to alter the current being
measured.
R
+A_
+V_
+ -
V1
I1
R1
V2
I2
I
R2
V

In parallel combination potential differences are equal, currents
are added.
V1 = V2 = V..
..I1 + I2 = I..
[This is because a charge must pass through R1 or R2]
Equivalent resistance :
R1
Req
R2
I
I
I1 + I2 = I
V1 V2
V
+
=
R1 R 2
R eq

1
1
1


R1 R2
R eq
Combination of resistors:
Ex:12-13-14-15-16-17-18
a) Series combination:
I
V1
V2
R1
R2
HOMEWORK: pr.15-16-17-18-19
MULTIMEDIA: akadem.cerway3, electromag.
DEMONSTRATION: measurement of current and
voltage
EXPERIMENT: ohm’s law
V

In series combination currents are equal, potential
differences are added.
I1 = I2 = I..
..V1 + V2 = V..
[That is because charges pass through R1 and R2
losing energy on both of them.]
Equivalent resistance:
V
V
R1
Req
R2
TEACHER:
I
I
V = V1 + V2
I Req = I R1 + I R2
Req = R1 + R2..
DIRECTOR: