Save
...
Unit 2: Electricity
2.4 Energy Transfers in Electrical Appliances
2.4.1 Power
Save
Share
Learn
Content
Leaderboard
Share
Learn
Cards (78)
What is the formula for power in terms of energy and time?
P
=
P =
P
=
E
t
\frac{E}{t}
t
E
What is the alternative formula for power using voltage and current?
P
=
P =
P
=
I
V
IV
I
V
1 watt is equivalent to 1 joule of energy converted per second.
True
In the formula
P
=
P =
P
=
E
t
\frac{E}{t}
t
E
, 't' represents the time
What does 'V' represent in the formula
P
=
P =
P
=
V
I
VI
V
I
?
Voltage
What is the unit of power in the SI system?
Watt
The formula
P
=
P =
P
=
E
t
\frac{E}{t}
t
E
relates power to energy and time
The formula
P
=
P =
P
=
V
I
VI
V
I
is more direct for measuring energy use over time.
False
Power is the rate at which electrical energy is converted into other forms of
energy
The SI unit of power is the watt (W).
True
Power can be calculated using energy and
time
What does 'E' represent in the formula
P
=
P =
P
=
E
t
\frac{E}{t}
t
E
?
Energy
The formula
P
=
P =
P
=
V
I
VI
V
I
relates power to voltage and current.
True
In the formula
P
=
P =
P
=
V
I
VI
V
I
, 'I' represents the current
The formula
P
=
P =
P
=
E
t
\frac{E}{t}
t
E
calculates power directly from energy and time.
True
If an appliance uses 600 joules of energy in 10 seconds, what is its power?
60 watts
If an appliance uses 600 joules of energy in 10 seconds, its power is
60
Power is the rate at which electrical energy is converted into other forms, such as heat, light, or
kinetic
energy.
If an appliance uses 600 joules of energy in 10 seconds, its power is 60 watts.
True
Power is measured in watts (W), where 1 watt equals 1 joule per
second
.
1 watt (W) equals 1 joule (J) of energy converted per
second
.
Match the quantity with its unit and symbol:
Power ↔️ Watt (W)
Energy ↔️ Joule (J)
Time ↔️ Second (s)
In the formula
P
=
P =
P
=
E
t
\frac{E}{t}
t
E
, 'E' represents the energy converted in joules.
What is the formula for power in terms of voltage and current?
P
=
P =
P
=
V
×
I
V \times I
V
×
I
The formula
P
=
P =
P
=
E
t
\frac{E}{t}
t
E
calculates power using energy and time, while
P
=
P =
P
=
V
×
I
V \times I
V
×
I
uses voltage and current.
True
What is the definition of a joule?
Work done or heat generated
1 watt is equal to 1 joule of energy converted per
second
.
True
Power can also be calculated using the formula
P
=
P =
P
=
I
V
IV
I
V
, where 'I' represents the current in amperes.
The formula
P
=
P =
P
=
I
V
IV
I
V
is used when voltage and current are known, instead of energy and time.
True
In the formula P = IV, P is measured in
watts
.
True
If a device operates at 120 volts and draws 5 amperes of current, its power is
600
The power formula using voltage and current is
P = V × I
Power is directly proportional to both voltage and
current
.
True
What is the formula for calculating power using energy and time?
P
=
P =
P
=
E
t
\frac{E}{t}
t
E
An appliance using 600 joules of energy in 10 seconds has a power of 60
watts
.
True
The formula
P
=
P =
P
=
E
t
\frac{E}{t}
t
E
calculates power directly from energy and time
What are the units of energy and time in the formula
P
=
P =
P
=
E
t
\frac{E}{t}
t
E
?
Joules (J) and seconds (s)
What is power measured in?
Watts
An appliance that uses 600 joules of energy in 10 seconds has a power of
60 watts
.
True
A second is the base unit for
time
See all 78 cards