1. The SI unit of length is:
Answer:
Explanation:
In the International System of Units (SI), the standard unit of length is the meter.
2. Which of the following is NOT a fundamental unit?
Answer:
Explanation:
Newton is a derived unit of force. The fundamental units are basic units from which other units are derived.
3. The number of significant figures in 0.005300 is:
Answer:
Explanation:
Only the digits 5, 3 are considered significant. Leading zeros and trailing zeros in a decimal number are not counted as significant figures.
4. The SI unit of time is:
Answer:
Explanation:
In the International System of Units (SI), the standard unit of time is the second.
5. The study of standards for different physical quantities is known as:
Answer:
Explanation:
Metrology is the science of measurement and its application.
6. What is the value of the speed of light in a vacuum?
Answer:
Explanation:
The speed of light in a vacuum is approximately 3 x 10^8 meters per second.
7. Which of the following is the smallest measurable length?
Answer:
Explanation:
Planck length, approximately 1.6 x 10^-35 meters, is the smallest length scale at which current theories of physics are believed to remain valid.
8. The prefix ‘Mega’ denotes:
Answer:
Explanation:
In the metric system, the prefix ‘Mega’ denotes a factor of one million, or 10^6.
9. Which of the following has the dimension [M^1L^1T^-2]?
Answer:
Explanation:
The dimensional formula of force is [M^1L^1T^-2].
10. How many base units are there in the SI system?
Answer:
Explanation:
There are 7 base units in the SI system: meter, kilogram, second, ampere, kelvin, mole, and candela.
11. The unit of luminous intensity in the SI system is:
Answer:
Explanation:
Candela is the SI unit of luminous intensity.
12. A decibel is a unit used to measure:
Answer:
Explanation:
A decibel (dB) is commonly used to express the intensity or level of sound.
13. The accuracy of a measurement refers to:
Answer:
Explanation:
Accuracy indicates how close a measurement is to the true or accepted value.
14. The SI unit of electric current is:
Answer:
Explanation:
Ampere is the SI unit of electric current.
15. The amount of space occupied by a substance is called its:
Answer:
Explanation:
Volume is the quantity of three-dimensional space occupied by a substance or enclosed by a surface.
16. Which of these is a unit of frequency?
Answer:
Explanation:
Hertz is the SI unit of frequency, defined as one cycle per second.
17. The uncertainty in a measurement is known as:
Answer:
Explanation:
Error is the difference between the measured value and the true value.
18. What does the prefix ‘kilo’ represent?
Answer:
Explanation:
In the metric system, the prefix ‘kilo’ denotes a factor of one thousand, or 10^3.
19. Which of the following is dimensionless?
Answer:
Explanation:
Refractive index is a ratio and hence, it doesn’t have any dimensions.
20. The correct representation of the unit of gravitational constant ‘G’ is:
Answer:
Explanation:
The gravitational constant, G, has units of m^3kg^-1s^-2.
21. A unit that is derived from the fundamental units is called:
Answer:
Explanation:
Derived units are combinations of the seven base SI units.
22. What represents the precision of an instrument?
Answer:
Explanation:
Resolution is the smallest measurable value that an instrument can detect.
23. The SI unit of temperature is:
Answer:
Explanation:
Kelvin is the SI unit of thermodynamic temperature.
24. Which of these is NOT a scalar quantity?
Answer:
Explanation:
Velocity has both magnitude and direction, making it a vector quantity.
25. The process of determining the value of some quantity in terms of a standard unit is called:
Answer:
Explanation:
Measurement is the comparison of an unknown quantity with a known or standard quantity.