EASY
Earn 100

If x vernier scale division is equal to Y main scale division where 1 M.S.D. is 1 cm, then find L.C.

Important Questions on Units and Measurements

EASY
A student measured the diameter of a small steel ball using a screw gauge of least count 0.001 cm. The main scale reading is 5 mm and zero division of the circular scale coincides with 25 divisions above the reference level. If the screw gauge has a zero error of -0.004 cm. the correct diameter of the ball is__________
MEDIUM
The period of oscillation of a simple pendulum is T=2πlg.  Measured value of l is 20.0 cm, known to 1 mm  accuracy and time for 100 oscillations of the pendulum is found to be 90 s using a wristwatch of 1 s resolution. The accuracy in the determination of g is 
MEDIUM
The vernier scale of an instrument has 50 divisions which coincide with 49 main scale divisions. If each main scale division is 0.5 mm, then using this instrument what would be the minimum inaccuracy (in mm) in the measurement of distance?
EASY
Distinguish between accuracy and precision.
EASY
Which of the following measurement is most precise?
EASY
In our daily life, is it essential to measure everything accurately?
EASY

A student measured the length of a rod and wrote it as 3.5 cm. Which instrument did he use to measure it?

EASY
The mean length of an object is 5 cm. Which of the following measurements is the most accurate?
MEDIUM
Time for 20 oscillations of a pendulum is measured as t1=39.6 st2=39.9 st3=39.5 s; What is the precision in the measurements? What is the accuracy of measurement?
EASY

Write T for the true statement and F for the false one. Correct the false statement(s).

Estimation is a very accurate method of measurement.

MEDIUM

The pitch of a screw gauge is 0.5 mm and its head scale has 50 divisions. The least count of the screw gauge is:

MEDIUM
Just as precise measurements are necessary in science, it is equally important to be able to make rough estimates of quantities using rudimentary ideas and common observations. Think of ways by which you can estimate the following (where an estimate is difficult to obtain, try to get an upper bound on the quantity): "the total mass of rain-bearing clouds over India during the Monsoon".
MEDIUM
Three measurements of the time for 20 oscillations of a pendulum give t1=39.6 st2= 39.9 s and t3=39.5 s. What is the precision in the measurements? What is the accuracy of the measurements?
EASY
Which of the following measurements is the most precise?
MEDIUM
A student measures the thickness of a human hair by looking at it through a microscope of magnification 100. He makes 20 observations and finds that the average width of the hair in the field of view of the microscope is 3.5 mm. What is the estimate on the thickness of hair in mm
EASY

If ten students are asked to measure the length of a piece of cloth up to a mm, using a metre scale, do you think their answers will be identical? Give reasons.

EASY

Measure of two quantities along with the precision of respective measuring instrument is

A = 2.5 m s-1 ± 0.5 m s-1

B = 0.10 s ± 0.01 s

The value of AB will be 

MEDIUM
The mean length of an object is 5cm. Which of the following measurement is most accurate?
EASY
To calculate the effective length of pendulum, we measure :-