Extra Assignment 2008 – Submit by 5th May 2008
BSc Systems 2
Paul Flynn
1.) If a current
of 3 A is divided
by the following
circuit, the
current flowing
through the 4
Ohm resistor is
…
3A
1
2
2A
3
1,5 A
4
1A
2.) The diagram at the
right shows part of a
circuit into which a
current I is flowing.
Which ammeter
shows the highest
reading?
A1
1
2
A2
3
A3
4
All three
ammeters
give the
same
reading
3.) The diagram to the right represents
a part of a circuit containing an ohmic
resistor, a voltmeter and an ammeter.
If the reading on the ammeter A
increases the reading on voltmeter V …
increases in the same ratio.
1
2
increases, but not in the
same ratio.
3
remains unchanged.
4
decreases in the same ratio.
1
BSc Systems 2
Extra Assignment 2008 – Submit by 5th May 2008
Paul Flynn
4.) A battery is connected to two identical light bulbs in parallel as well as another
identical bulb in series. An ammeter and a voltmeter are also connected as shown in
the circuit diagram below.
One of the light bulbs connected in parallel is unscrewed. How will the ammeter and
the voltmeter readings change?
Ammeter reading
Voltmeter reading
1
increases
increases
2
increases
decreases
3
increases
unchanged
4
decreases
decreases
5.) A learner connects a circuit as shown in the diagram to the
right. He/she uses a source of electricity with an electromotive
force (emf) of 12 V.
Which one of the following best gives the ammeter and voltmeter
readings which the learner is most likely to get with this circuit?
Ammeter reading
Voltmeter reading
1
reads zero
reads zero
2
reads zero
reads 12 V
3
very large reading
reads zero
4
very large reading
reads 12 V
2
Extra Assignment 2008 – Submit by 5th May 2008
BSc Systems 2
Paul Flynn
6.) Three
identical
resistors of 4 Ω
are connected
to give a
combined
resistance of 6
Ω. Which of the
following
circuit
diagrams
illustrates how
this was done?
1
I
2
II
3
III
4
IV
7.) In the circuit to the right
B1, B2 and B3 are identical light
bulbs. The internal resistance
of the battery can be ignored.
Which statement is true
regarding the relative
brightness of the bulbs?
The three bulbs glow
with the same
1
brightness.
B2 and B3 glow with
the same brightness
2
but brighter than B
B2 and B3 glow with
the same brightness
3
but less brightly than
B1 .
B1 glows brighter
than B2 while B2 in
4
turn glows brighter
than B3.
3
Extra Assignment 2008 – Submit by 5th May 2008
BSc Systems 2
Paul Flynn
8.) Two identical light bulbs, X
and Y, are connected in series as
shown in the sketch to the right.
How will the brightness of the
bulbs change if switch S is
closed?
X
Y
1
brighter
brighter
2
dimmer
dimmer
3
brighter not lit up
4
not lit up brighter
9.) A student connects three
identical resistors as shown
in the sketch to the right.
The potential difference
across the battery is 12 Volt.
What are the readings on V1
and V2 respectively?
V1
V2
1
4
8
2
6
6
3
8
4
4
9
3
10.) A 9 V battery is composed of six 1,5 V cells, which are connected in series. Each
cell has an internal resistance of 0,2 Ω. What is the highest current that can be
obtained from such a battery?
1
7,5 A
2
1,5 A
3
1,2 A
4
0,3 A
4
BSc Systems 2
Extra Assignment 2008 – Submit by 5th May 2008
Paul Flynn
11.) Consider the electric
circuit shown in the
diagram at the right.
The reading on the
voltmeter V is ...
0V
A
B
2V
C
4V
D
6V
12.) Two light bulbs P and Q are identical in all respects, except that P's filament is
thicker than Q's. If the same potential difference is applied to each, then …
A
P will burn brighter because it has the greater resistance.
B
Q will burn brighter because it has the greater resistance.
C
P will burn brighter because it has the lower resistance.
Q will burn brighter because it has the lower resistance.
D
13.) The ammeter and the battery in
the sketch to the right have negligible
resistance. The resistors are in
parallel. What will happen to the
ammeter and voltmeter readings
when switch S is closed?
ammeter
voltmeter
reading
reading
A
increases
unchanged
B
increases
increases
C
decreases
decreases
D
decreases
increases
5
BSc Systems 2
Extra Assignment 2008 – Submit by 5th May 2008
Paul Flynn
14.) In the circuit shown the bulb marked 2R has twice the resistance of the bulb
marked R. Compared with bulb 2R, the current in bulb R and its brightness
compared to the other bulb, is …
current in brightness in
2R
R
A
larger
brighter
B
larger
dimmer
C
smaller
brighter
D
smaller
dimmer
15.) Mary has connected four identical light bulbs in a circuit as shown to the right.
She observes that the brightness of bulb A varies if some of the switches are closed.
In which case will bulb A burn brightest?
C
S1 closed with S2
and S3 open
S1 and S2 closed
with S3 open
S1, S2 and S3
closed
D
S1, S2 and S3 open
A
B
16.) Two identical light bulbs X and Y, which are rated at 60 W; 240 V, are
connected in series to a 240 V source as shown in the diagram below. If point A in
the circuit is now connected to point B by a piece of copper wire with very low
resistance, how will the brightness of each bulb change?
6
BSc Systems 2
A
B
C
D
Extra Assignment 2008 – Submit by 5th May 2008
Paul Flynn
Both X and Y
will burn
brighter.
Both X and Y
will burn less
brightly.
X will burn
brighter and Y
will not burn.
Y will burn
brighter and X
will not burn.
17.) A battery is connected to a small lamp. If a second identical lamp is connected
in series with the first, what will happen to the current provided by the battery?
A
it will decrease
B
it will remain the same
C
it will increase
D
it will become zero
18.) A 200 V electrical outlet is protected by a circuit breaker. The circuit breaker
will cut out if the current drawn from the outlets exceeds 16 A. A 1000 W toaster
and a 2000 W kettle can be connected to the outlet, either singly, or both in parallel
using a double adapter. Which use of the appliances will trip the circuit breaker?
A
the toaster used on its own
B
the kettle used on its own
C
the toaster and the kettle
together
D
none of the above
7
BSc Systems 2
Extra Assignment 2008 – Submit by 5th May 2008
Paul Flynn
19.) Two light bulbs are marked 230 V; 75 W and 230 V; 150 W. If the first bulb has
a resistance R, then the resistance of the second is …
A
¼R
B
½R
C
2R
D
4R
20.) 10. Two resistors of resistance 2R and 3R are connected in series with a battery,
which has an emf of E and an internal resistance R. What is the potential difference
across the resistor of resistance 2R?
A
E/3
B
2E/5
C
E/2
D
2E
8