Questions
The atomic standard of time is based on the periodic vibrations produced in which of the following?
- Balance wheel
- Quartz
- Pendulum
- Cesium atoms
- None of these
Which of the following units does not belong to the group of non-SI unit?
Roentgen, Barn, Carat, Hour, Kilogram, Quintal, Degree
- Roentgen is not a SI unit.
- Barn is not a SI unit.
- Hour is not a SI unit.
- Kilogram is a SI unit.
- Degree is not a SI unit.
SI multiples of metre are used with different names. Value equal to 10-9m is called _____________ and value equal to 109m is called ___________.
- micrometer, megameter
- millimeter, kilometer
- attometer, exameter
- centimeter, hectometer
- nanometer, gigameter
________ is used to measure lengths ranging from 10-3m to 10-2m.
- Screw guage
- Meter scale
- Spherometer
- Laser tapes
- Vernier callipers
Which of the following errors is there, if the temperature graduations of a thermometer read 104 °C at the boiling point of water at STP?
- Imperfection in procedure
- Instrumental error
- Least count error
- Personal errors
- None of these
Which of the following matches incorrectly with its unit?
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| (a) Luminous intensity | mol |
| (b) Thermodynamic temperature | cd |
| (c) Mass | Kg |
| (d) Electricity | A |
- (a) and (c)
- (a) and (b)
- (b) and (d)
- only (d)
- only (c)
Suppose the true value of a certain length is near 3.678 cm. In one experiment, using a measuring instrument of resolution 0.1 cm, the measured value is found to be 3.5 cm, while in another experiment using a measuring device of resolution, say 0.01 cm, the length is determined to be 3.38 cm. What is the conclusion?
- In the first measurement, accuracy is more and precision is less
- In the second measurement, accuracy is less and precision is more
- In the first measurement, accuracy and precision is more
- In the second measurement, accuracy and precision is more
- None of these
If a vernier calliper is used for measurement and the zero mark of vernier scale does not coincide with the zero mark of the main scale, then which of the following errors will be shown in the result?
- Least count error
- Observation error
- Random error
- Instrumental error
- None of these
Which of the following steps can reduce the least count error in a measurement?
(a) Using instruments of higher precision
(b) Improving experimental techniques
(c) Always take an idea of actual value before measuring
(d) Repeating the observations several times
- only (a)
- (a), (b) and (c)
- (a), (b), (c) and (d)
- (b), (c) and (d)
- only (c)
How many significant figures does the length of an object have after measurement 4567.81?
- 5
- 4
- 7
- 6
- None of these
The preceding digit is raised by 1, if the insignificant digit to be dropped, (the underlined digit in this case) is ____________ .
- less than 5
- more than 5
- equal to 5
- equal to zero
- none of these
The metre is the length of the path travelled by ________________ in _________________ during a time interval of 1/299, 792, 458 of a second.
- sound, vacuum
- sound, air
- light, vacuum
- light, air
- none of these
Suppose the values obtained in several measurements are a1, a2, a3...., an. If the arithmetic mean of these values = a mean, what will be the formula to find the error in the third measured value?
- a3
- (a1 + a2 + a3)/an
- a mean - a3
- a mean/ a3
- none of these
Large distances (such as the distance of a planet or a star from the earth) cannot be measured directly with a meter scale. It is done by ________.
- vernier callipers
- spherometer
- screw gauge
- parallax method
- None of these
Students were asked to calculate the length, mass and time in CGS unit. In which of the following units should their answer be?
- Length - Kilometre, Mass - Gram, Time - Second
- Length - Milimetre, Mass - Milligram, Time - Second
- Length - Centimetre, Mass - Gram, Time - Second
- Length - Foot, Mass - Gram, Time - Minute
- Length - Metre, Mass - Kilogram, Time - Minute