ANSWER ANY
TWENTY
1. When a voltage V of 12.2 V is
applied to a DC motor, the current I in the motor is 0.20 A. Which one
of the following is the output power VI of the motor given to the
correct appropriate number of significant digits?
A. 2 W
B. 2.4 W
C. 2.40 W
D. 2.44 W
(1)
2. Which one of the following units
is a unit of energy?
A. eV
B. Ws–1
C. Wm–1
D. Nms–1
(1)
3. Natalie measures the mass and speed of a
glider. The percentage uncertainty in her measurement of the mass is 3% and in
the measurement of the speed is 10%. Her calculated value of the kinetic energy
of the glider will have an uncertainty of
A. 30%.
B. 23%.
C. 13%.
D. 10%.
(1)
4. The ratio 
is approximately equal to
is approximately equal to
A. 10–15.
B. 10–8.
C. 10–5.
D. 10–2.
(1)
5. Which one of the following lists a
fundamental unit and a derived unit?
|
A.
|
ampere
|
second
|
|
B.
|
coulomb
|
kilogram
|
|
C.
|
coulomb
|
newton
|
|
D.
|
metre
|
kilogram
|
(1)
6. A student measures the current in a
resistor as 677 mA for a potential difference of 3.6 V. A calculator shows the
resistance of the resistor to be 5.3175775 Ω. Which one of the following
gives the resistance to an appropriate number of significant figures?
A. 5.3 Ω
B. 5.32 Ω
C. 5.318 Ω
D. 5.31765775 Ω
(1)
7. Two forces of magnitudes 7 N and 5 N act
at a point. Which one of the following is not a possible value
for the magnitude of the resultant force?
A. 1 N
B. 3 N
C. 5 N
D. 7 N
(1)
8. A student measures a distance several
times. The readings lie between 49.8 cm and 50.2 cm. This measurement is best
recorded as
A. 49.8 ± 0.2 cm.
B. 49.8 ± 0.4 cm.
C. 50.0 ± 0.2 cm.
D. 50.0 ± 0.4 cm.
(1)
9. Which two values of temperature are
equivalent to the nearest degree when measured on the Kelvin and on the Celsius
scales of temperature?
|
|
Kelvin
scale
|
Celsius
scale
|
|
A.
|
40
|
313
|
|
B.
|
273
|
100
|
|
C.
|
313
|
40
|
|
D.
|
373
|
0
|
(1)
10. The diameter of the nucleus of a hydrogen
atom is of the order of
A. 10–8 m.
B. 10–15 m.
C. 10–23 m.
D. 10–30 m.
(1)
11. The unit, the electron-volt is equivalent
to
A. 1.6 × 10+19 J.
B. 9.1 × 10+31 J
C. 1.6 × 10–19 J.
D. 9.1 × 10–31 J.
(1)
12. The power dissipated in a resistor of
resistance R carrying a current I is equal to I2R.
The value of I has an uncertainty of ±2% and the value of R has
an uncertainty of ±10%. The value of the uncertainty in the calculated power
dissipation is
A. ±8%.
B. ±12%.
C. ±14%.
D. ±20%.
(1)
13. The number of heartbeats of a person at
rest in one hour, to the nearest order of magnitude is
A. 101.
B. 102.
C. 104.
D. 106.
(1)
14. The diameter of a proton is of the order of
magnitude of
A. 10–12 m.
B. 10–15 m.
C. 10–18 m.
D. 10–21 m.
(1)
15. An ammeter has a zero offset error. This
fault will affect
A. neither the precision nor the accuracy of
the readings.
B. only the precision of the readings.
C. only the accuracy of the readings.
D. both the precision and the accuracy of the
readings.
(1)
16. Which one of the following is a
scalar quantity?
A. Pressure
B. Impulse
C. Magnetic field strength
D. Weight
(1)
17. For an object to be in translational
equilibrium
A. it must be at rest.
B. it must be moving with a constant
acceleration.
C. no external force must be acting on it.
D. the net force acting on it must be zero.
(1)
18. Which one of the following is a
fundamental unit?
A. Coulomb
B. Ohm
C. Volt
D. Ampere
(1)
19. When a force F of (10.0 ± 0.2) N is
applied to a mass m of (2.0 ± 0.1) kg, the percentage uncertainty attached to the value of
the calculated acceleration 
is
is
A. 2 %.
B. 5 %.
C. 7 %.
D. 10 %.
(1)
20. When a force F of (10.0 ± 0.2) N is
applied to a mass m of (2.0 ± 0.1) kg, the absolute
uncertainty attached to the value of the calculated acceleration is
is
A. ± 0.1.
B. ± 0.2.
C. ± 0.3.
D. ± 0.4.
(1)
21. Which one of the following is a
fundamental unit?
A. Ohm
B. Tesla
C. Volt
D. Candela
(1)
22. Which of the following gives the
approximate ratio of the separation of the molecules in water and in steam at
atmospheric pressure?
|
|
Water
:
|
Steam
|
|
A.
|
1
:
|
1
|
|
B.
|
1
:
|
10
|
|
C.
|
1
:
|
100
|
|
D.
|
1
:
|
1000
|
(1)
23. The resistive force F acting on a
sphere of radius r moving at speed v through a liquid is given by
F
= cvr
where c is a constant. Which of
the following is a correct unit for c?
A. N
B. N s–1
C. N m2 s–1
D. N m–2 s
(1)
24. Which of the following is the best
estimate, to two significant digit, of the quantity shown below?
A. 1.5
B. 2.0
C. 5.8
D. 6.4
(1)
25. The electron volt is defined as
A. a unit of energy exactly equal to 1.6 × 10–19 J.
B. a fraction 
of the ionization energy of atomic hydrogen.
of the ionization energy of atomic hydrogen.
C. the energy gained by an electron when it
moves through a potential difference of 1.0 V.
D. the energy transfer when 1.0 C of charge
moves through a potential difference of 1.0 V.
(1)
26. The order of magnitude of the weight of an
apple is
A. 10–4 N.
B. 10–2 N.
C. 101N.
D. 102 N.
(1)
27. Which one of the following contains
three fundamental units?
|
A.
|
Metre
|
Kilogram
|
Coulomb
|
|
B.
|
Second
|
Ampere
|
Newton
|
|
C.
|
Kilogram
|
Ampere
|
Kelvin
|
|
D.
|
Kelvin
|
Coulomb
|
Second
|
(1)
28. The reading of a constant potential
difference is made four times by a student. The readings are
1.176 V
1.178 V
1.177 V
1.176 V
1.178 V
1.177 V
1.176 V
The student averages these readings
but does not take into account the zero error on the voltmeter. The average
measurement of the potential difference is
A. precise and accurate.
B. precise but not accurate.
C. accurate but not precise.
D. not accurate and not precise.
(1)
29. The definition of the unit of current, the
ampere, is based on
A. the force per unit charge on a conductor
in a uniform magnetic field.
B. the force per unit mass on parallel
current-carrying conductors.
C. the charge per unit time delivered by a
cell of e.m.f. 1.0 V.
D. the charge passing a resistor per unit
time in an electrical circuit.
(1)
30. The volume V of a cylinder of height
h and radius r is given by the expression
V
= πr2h.
In a particular experiment, r is
to be determined from measurements of V and h. The uncertainties
in V and in h are as shown below.
|
V
|
± 7 %
|
|
h
|
± 3 %
|
The approximate uncertainty in r is
A. 10 %.
B. 5 %.
C. 4 %.
D. 2 %.
(1)
31. The ratio 
to the nearest order of magnitude is
to the nearest order of magnitude is
A. 102.
B. 105.
C. 1010.
D. 1015.
(1)
32. The kWh is equal to
A. 1.0 × 103 J.
B. 3.6 × 103 J.
C. 6.0 × 104 J.
D. 3.6 × 106 J.
(1)
33. The diagram below shows the position of the
meniscus of the mercury in a mercury-in-glass thermometer.
Which of the following best expresses
the indicated temperature with its uncertainty?
A. (6.0 ± 0.5)°C
B. (6.1 ± 0.1)°C
C. (6.2 ± 0.2)°C
D. (5.2 ± 0.5)°C
(1)
34. Which of the following represents two
vector quantities?
A. distance, acceleration
B. kinetic energy, work
C. force, momentum
D. electric field strength, electric
potential
(1)
35. An electric motor, with an input power of
250 W, produces 200 W of mechanical power. The efficiency of the motor
is
A. 20 %.
B. 25 %.
C. 55 %.
D. 80 %.
(1)
36. The radius of a loop is measured to be
(10.0 ± 0.5) cm. Which of the following is the best estimate of the uncertainty
in the calculated area of the loop?
A. 0.25 %
B. 5 %
C. 10 %
D. 25 %
(1)
37. The diagram below shows a boat that is
about to cross a river in a direction perpendicular to
the bank at a speed of 0.8 ms–1.
The current flows at 0.6 ms–1 in the direction shown.
The magnitude of the displacement of
the boat 5 seconds after leaving the bank is
A. 3 m.
B. 4 m.
C. 5 m.
D. 7 m.
(1)
38. 
(1)
(1)
39.
The Precision and Accuracy
are related as,
A. Precision cannot be reduced but Accuracy can
be reduced.
B. Precision
can be reduced but Accuracy can be reduced
to ZERO.
C. Precision
and Accuracy cannot be reduced.
D. Precision can be reduced to ZERO but Accuracy
can only be reduced.
40. The Correct length of a pen for multiple
readings of 5.5cm, 5.4cm, 5.6cm is,
A.
5.5 ± 0.1 cm
B. 5.5 ± 0.15 cm
C. 5.5 ± 0.01 cm
D. 5.5 ± 021 cm
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