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WorksheetsP2 c Power (GCSE Elec)
Total questions: 27
Worksheet time: 27mins
Which symbols are used for the units of current and of resistance?
A
B
C
D
What moves when we say that there is current?
inductors
conductors
electrons
atoms
Which one of the following quantities is equivalent to 1 W?
1 V/A
1 Ω • m
1 V • A
1 V/Ω
A resistor operated at 140 V dc is rated at 1.40 kW.
(a) What is the normal operating current through the resistor?
(a) 10 A .
(a) 14 A .
(a) 1 A .
(a) 0.010 A .
An instrument is rated at 240 W if it is connected across a 120-V dc power supply.
(a) What current does it draw under normal operation?
(a)
A 200-W light bulb is connected across a 100-V dc power supply. What current will flow through this bulb?
0.90 A
0.36 A
0.60 A
2.0 A
A 100-W light bulb is operated by a 110-V dc source. What is the resistance of this bulb?
Power = V.I and you know that V=R.I (ohm's law)
100 Ω
8.0 × 10-3 Ω
120 Ω
240 Ω
What is meant by Power?
Speed at which work is done
Rate of consumption of energy
Rate at which an electron moves inside a circuit
None of the above
Calculate the electrical energy consumed in Joules if a toaster of 60 W is used for 30 minutes?
108000J
1.08J
1080000J
10.8J
A lamp consumes 500 J of electrical energy in 20 sec. What is the power of the lamp?
55 W
0.25W
65W
25W
DC
AC
rectified current
non rectified current
What is the formula of electric power?
P= I x V
V= P x I
I= P x V
P= I/V
What is the potential difference of the circuit that has a current of 30A and 600W?
10 V
20 V
30 V
40 V
Current of 5A flows through microwave oven connected to a 110V source? What is the power supplied to the microwave oven?
660 Watts
500 Watts
550 Watts
600 Watts
Power =
Current x Voltage
Current x Energy
Energy x Power
What is the point of a fuse? (Select the two best options)
The fuse will break or melt if it gets
The fuse will break the circuit
The fuse is just there for looks
One watt is equal to,
one meter per second
one Joule per second
One ampere per second
one farad per second
When the switch is closed, the current in the cell is 16 A.
Calculate the charge that passes through the cell in 25 s.
[charge transferred = current × time taken]
Calculate charge when a current of 2A flows for 2 minutes
(a)
Calculate the charge when 2kA flows for 5ms
(a)
