The radius of the Earth is approximately 6.4 × 10^6 m, and the radius of the Moon is approximately 1.7 × 10^6 m. A student wishes to build a scale model of the Solar System in the classroom, using a football of radius 0.12m to represent the Earth. Which object would best represent the Moon?
basketball
cherry
golf ball
tennis ball
A micrometer screw gauge is used to measure the diameter of a copper wire. The reading with the wire in position is shown in diagram 1. The wire is removed and the jaws of the micrometer are closed. The new reading is shown in diagram 2. What is the diameter of the wire?
1.90 mm
2.45 mm
2.59 mm
2.73 mm
A digital meter has an accuracy of ±1%. The meter is used to measure the current in an electrical circuit. The reading on the meter varies between 3.04A and 3.08A. What is the value of the current, with its uncertainty?
(3.06 ± 0.02)A
(3.06 ± 0.04)A
(3.06 ± 0.05)A
(3.06 ± 0.07)A
What is the unit of resistance when expressed in SI base units?
kg.m^2.s^–2.A^–1
kg.m^2.s^–3.A^–2
kg .m.s^–2.A^–1
kg.m.s^–3.A^–1
Three of these quantities have the same unit. Which quantity has a different unit?
energy/distance
force
power × time
rate of change of momentum
Which unit can be expressed in base units as kg.m^2.s^–2?
joule
newton
pascal
watt
What is equivalent to 2000 microvolts?
2µJ.C^–1
2 mV
2 pV
2000 mV
The Planck constant 'h' has SI units J.s. Which equation could be used to calculate the Planck constant?
h = DE/v where D is distance, E is energy and v is velocity.
h = v/D where v is velocity and D is distance.
h = 1/4 π E where E is electric field strength.
h = Fr^2/m where F is force, r is radius and m is mass.
Which is an SI base unit?
current
gram
kelvin
volt
Osmium, a naturally occurring element, has a density of 23000 kg.m^–3. What is also a value of the density of osmium?
2.3 × 10^4 µg.cm^–3
2.3 × 10^4 g.cm^–3
2.3 kg.cm^–3
2.3 × 10^–2 kg.cm^–3
Which expression gives an SI base quantity?
A charge per unit time.
B force per unit area.
C mass per unit volume.
D work done per unit distance.
Which list contains only scalar quantities?
A area, length, displacement
B kinetic energy, speed, power
C potential energy, momentum, time
D velocity, distance, temperature
A micrometer is used to measure the 28.50 mm width of a plastic ruler. The micrometer reads to the nearest 0.01 mm. What is the correct way to record this reading?
A 0.02850 ± 0.01 m
B 0.0285 ± 0.001 m
C (2.850 ± 0.001) × 10^–2 m
D (2.850 ± 0.001) × 10^–3 m
The sides of a wooden block are measured with calipers. The lengths of the sides are measured as 20.0 mm, 40.0 mm and 10.0 mm. The calipers can measure with an absolute uncertainty of ± 0.1 mm. What is the percentage uncertainty in the calculated volume of the block?
A 0.3%
B 1.8%
C 3.8%
D 30%
Which quantity with its unit is correct?
A acceleration of a bicycle = 1.4 m.s^–1
B electric current in a lamp = 0.25A.s^–1
C electric potential difference across a battery = 8.0 J.C^–1
D kinetic energy of a car = 4500 N.m^–1
Which two units are not equivalent to each other?
A N.m and kg.m^2.s^–2
B N.s and kg.m.s^–1
C J.s^–1 and kg.m^2.s^–3
D Pa and kg.m s^–2
What could reduce systematic errors?
A averaging a large number of measurements
B careful calibration of measuring instruments
C reducing the sample size
D repeating measurements
The power loss P in a resistor is calculated using the formula P = V^2/R. The percentage uncertainty in the potential difference V is 3% and the percentage uncertainty in the resistance R is 2%. What is the percentage uncertainty in P?
4%
7%
8%
11%
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