The Datafile PD-CD 5/DATAFILE_PDCD5.iso/education/b/mcphysics/!MChoice/Default/Circuits

Text File | 1994-08-30 | 3KB | 169 lines

@In electric circuits the correct name for a 'battery' is:
Cell
Power supply
Volts

@What is the correct symbol for relay coil?
#cir3
Symbol 1
Symbol 2
Symbol 3

@What is the correct symbol for a fixed resistor?
#cir3
Symbol 2
Symbol 5
Symbol 4

@What is the correct symbol for a thermistor?
#cir3
Symbol 3
Symbol 5
Symbol 4

@What is the correct symbol for a variable resistor?
#cir3
Symbol 4
Symbol 2
Symbol 3

@What device do you use to measure the current in a circuit?
Ammeter
Voltmeter
Ohm meter

@If there is a gap in a wire in an electric circuit then:
Nothing works
It does not work as well
It makes no difference to the way the circuit works

@If a resistance is put into a circuit then the overall current flowing is:
Reduced
Just the same
Increased

@The positive connection on an Ammeter should be connected to:
Positive on the cell
Negative on the cell
Both positive & negative on the cell

@A switch turns the current in a circuit on and off because:
It makes a gap in the circuit which stops the current
It uses up the current
It gets warm

@Which of the symbols shown is a battery?
#cir2
Symbol 1
Symbol 2
Symbol 4

@Which of the symbols shown is a switch?
#cir1
Symbol 2
Symbol 1
Symbol 4

@Which one of the symbols shown is a diode?
#cir2
Symbol 4
Symbol 2
Symbol 3

@Which one of the symbols shown is a thermistor?
#cir2
Symbol 3
Symbol 1
Symbol 2

@What is the unit of resistance?
Ohm
Volt
Ampere

@40k Ohms can be written as:
40,000 Ohms
0.040 Ohms
400,000 Ohms

@What device is used to measure the flow of current?
Ammeter
Voltmeter
Thermocouple

@In electric circuits what letter is used for current?
I
A
p.d

@6,500 Ohms can be written as:
6.5k Ohms
65k Ohms
0.65k Ohms

@Potential difference is measured in:
Volts
Amps
Ohms

@Why are resistors placed in electrical circuits?
To reduce the current flowing
To increase the current flowing
To produce heat

@Two resistors, 470 and 1000 Ohms, are connected in series. Their combined resistance is:
1470 Ohms
470,000 Ohms
530 Ohms

@What is a potentiometer used for?
Varying the p.d in a circuit
Reducing the current that flows
Producing heat energy

@Two resistors, 500 and 1000, are connected in series. The p.d across the 1000 ohm compared to the 500 ohm resistor will be:
Double
Half
The same

@A device that usually only allows current to flow in one direction is called a:
Diode
Rheostat
Thermister

@A diode contains which of the following?
An anode and a cathode
An anode only
A base, collector and emitter

@Some diodes have a 'heat sink' connected to them. This is to:
get rid of excess heat
increase the diodes p.d
reduce the current flowing

@A device whose restance changes with temperature is called a:
Thermistor
L.E.D
L.D.R

@A device whose resistance changes with light intensity is called a:
L.D.R
Transistor
Rheostat

@What does a diode do?
Allows current to flow just one way through it
Change its resistance with temperature
Produce a sound when a p.d is applied to it

@A reed switch is affected by:
Magnetism
Heat
Light

@In circuits, LED's are often wired in series with a resistor. Why?
To protect them as they only need tiny currents
To prolong the life of the resistor
To make sure the effect on the circuit is minimal