Physical Quantities, Units and Measurement

Question 1

State the units for the following base quantities:
1) mass
2) length
3) time
4) current
5) temperature
6) amount of substance
7) intensity of light

Answer 1

1) kg
2) m
3) s
4) A
5) K
6) mol
7) candela

Question 2

In ascending order, state the prefixes and their symbols.

Answer 2

pico (p)
nano (n)
micro (µ)
milli (m)
centi (c)
deci (d)
kilo (k)
mega (M)
giga (G)
tera (T)

Question 3

State which of the factors affect the period of a pendulum:
1) mass of bob
2) length of pendulum
3) angle of swing

Answer 3

Ans: 2

The period increases with the length of the pendulum.

Question 4

Define accuracy.

Answer 4

The accuracy of a measurement is how close the measurement is to the true value of the quantity being measured.

Question 5

Define precision.

Answer 5

The precision of a measurement is how close a number of measurements of the same quantity agree with each other.

Question 6

How can the effects of random errors be reduced?

Answer 6

Repeat the experiment and take the average.

Question 7

Name the jaws present in a vernier caliper, and state each of their functions respectively.

Answer 7

Outside jaws: Measure the external diameter or width of an object
Inside jaws: Measure the internal diameter of an object