Page 1 - 10-phy-14 Current Electricity
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14C H A P T E R
Current Electricity
Experiment Verify Ohm's Law (using wire as conductor).
14.1 Date ________________
Every conductor has some resistance. When a potential difference is
Background applied across a conductor current starts flowing through it. The amount of
Information current flowing through a conductor depends upon the potential difference
applied as well as the resistance of the conductor.
Ohm's Law states that, “The current I passing through a conductor is
directly proportional to the potential difference V across it, provided its
temperature and physical state is not changed”.
Mathematically,
V µI
V = IR
! CAUTIONS where constant R is called the resistance of the conductor.
Electric current flows easily through materials called conductors such as
1. Clean the ends of copper, aluminium and iron etc. For current to flow, there must be a closed loop
connecting wires of conducting materials which includes electric cell, bulb or resistance, switch
with sandpaper. and connecting wires. This loop is called a circuit and its parts such as cell,
resistance and switch are called components. All components have at least two
2. A l l c o n n e c t i o n s connection points called terminals.
should be tight.
Energy is used up when current flows in the circuit. The cell provides
3. The voltmeter and energy to enable the current to flow around a circuit.
ammeter should be
connected in the Potential difference across a component specifies the energy lost as the
circuit such that their current flows through it. It is measured in volt.
positive ends are
connected to the Voltmeter
positive terminal of +V-
the power supply.
4. Note the zero errors
of the voltmeter and
ammeter, if any, Nichrome Wire
before starting the
experiment. - R
5. Always keep the key
open while making
connections of the A Ammeter
circuit.
6.Always set the +
rheostat slider at the
middle position +-
before starting the Rheostat Key
experiment. Power Supply
Fig. 14.1.1
30
Current Electricity
Experiment Verify Ohm's Law (using wire as conductor).
14.1 Date ________________
Every conductor has some resistance. When a potential difference is
Background applied across a conductor current starts flowing through it. The amount of
Information current flowing through a conductor depends upon the potential difference
applied as well as the resistance of the conductor.
Ohm's Law states that, “The current I passing through a conductor is
directly proportional to the potential difference V across it, provided its
temperature and physical state is not changed”.
Mathematically,
V µI
V = IR
! CAUTIONS where constant R is called the resistance of the conductor.
Electric current flows easily through materials called conductors such as
1. Clean the ends of copper, aluminium and iron etc. For current to flow, there must be a closed loop
connecting wires of conducting materials which includes electric cell, bulb or resistance, switch
with sandpaper. and connecting wires. This loop is called a circuit and its parts such as cell,
resistance and switch are called components. All components have at least two
2. A l l c o n n e c t i o n s connection points called terminals.
should be tight.
Energy is used up when current flows in the circuit. The cell provides
3. The voltmeter and energy to enable the current to flow around a circuit.
ammeter should be
connected in the Potential difference across a component specifies the energy lost as the
circuit such that their current flows through it. It is measured in volt.
positive ends are
connected to the Voltmeter
positive terminal of +V-
the power supply.
4. Note the zero errors
of the voltmeter and
ammeter, if any, Nichrome Wire
before starting the
experiment. - R
5. Always keep the key
open while making
connections of the A Ammeter
circuit.
6.Always set the +
rheostat slider at the
middle position +-
before starting the Rheostat Key
experiment. Power Supply
Fig. 14.1.1
30
