1. The number of base units for measuring physical quantities according to the SI system are ____
a) 1
b) 10
c) 7
d) 8
Answer: c
Explanation: There are 7 base units for measuring physical quantities according to the SI system. They are kilogram (kg) for mass, second (s) for time, kelvin (K) for temperature, ampere (A) for electric current, mole (mol) for the amount of a substance, candela (cd) for luminous intensity, and meter (m) for distance.
2. What is the unit for measuring intensity of light?
a) Candela
b) Lightyear
c) Meter
d) Mol
Answer: a
Explanation: The unit for measuring luminous intensity is Candela (cd). Lightyear and Meter are units of distance. Mol is unit of amount of a substance.
3. What is the full form of SI?
a) Standard International
b) System International
c) Scientific International
d) Science International
Answer: b
Explanation: The full for of SI is System International. It was first adopted in 1960 in the General Conference on Weights and Measures.
4. What is the standard unit of measurement of Force?
a) Newton
b) Joule
c) Meter
d) Newton-meter
Answer: a
Explanation: Newton is the SI unit for force. Joule and Newton-meter are the SI units for Energy and work. Meter is the SI unit for distance.
5. 89 Mega Joules can also be expressed as _____
a) 8900 Joules
b) 89000000 Joules
c) 89000 Joules
d) 890000 Joules
Answer: b
Explanation: 1 Mega Joule = 1000000 Joules. Therefore 89 Mega Joules = 89000000 Joules.
6. Convert 5 N to Dynes.
a) 500000 Dynes
b) 500 Dynes
c) 5 Dynes
d) 0.5 Dynes
Answer: a
Explanation: One Newton equals to 100000 Dynes, hence 5 N equal to 500000 Dynes. Dyne is unit of force in the CGS system.
7. Which of the following is not a system of units?
a) MKS
b) CGS
c) SI
d) Decibel
Answer: d
Explanation: MKS stands for meter-kilogram-second. CGS stands for centimeter-gram-second. SI stands for System international. Decibel is a unit of sound intensity.
8. What does a Voltmeter measure?
a) Voltage
b) Current
c) Length
d) Speed
Answer: a
Explanation: A voltmeter is used for measuring voltage. An ammeter is used for measuring current. A combination of both can be used to determine the resistance in a simple circuit.
9. What is the unit of measurement of solid angles?
a) Steradians
b) Degrees
c) Radians
d) Grades
Answer: a
Explanation: AS plane angles are measured in radians, in the same way solid angles are measured in steradians. A solid angle can be interpreted as the 3-dimensional form of a plane angle.
10. Which of the following system matches with the SI unit system?
a) FPS
b) MKS
c) CGS
d) American system
Answer: b
Explanation: The MKS system uses the same fundamental units as the SI system. It uses meter for distance, kilogram for mass, and second for time. These are all present as fundamental units in the SI system.
11. Which of the following is a unit of temperature?
a) Degree
b) Meter
c) Second
d) Fahrenheit
Answer: d
Explanation: Fahrenheit is the unit for temperature. Other units include Celsius and Kelvin.