In a screw gauge, there are 100 divisions on the circular scale and the main scale moves by $05 \,mm$ on a complete rotation of the circular scale The zero of circular scale lies $6$ divisions below the line of graduation when two studs are brought in contact with each other When a wire is placed between the studs, $4$ linear scale divisions are clearly visible while $46^{\text {th }}$ division the circular scale coincide with the reference line. The diameter of the wire is _____$\times 10^{-2} mm$
In a screw gauge, there are 100 divisions on the circular scale and the main scale moves by $05 \,mm$ on a complete rotation of the circular scale The zero of circular scale lies $6$ divisions below the line of graduation when two studs are brought in contact with each other When a wire is placed between the studs, $4$ linear scale divisions are clearly visible while $46^{\text {th }}$ division the circular scale coincide with the reference line. The diameter of the wire is _____$\times 10^{-2} mm$
Correct Answer: 27
Solution and Explanation
Least count
Least count
Positive Error
Reading of Diameter MSR
Positive zero error
Top JEE Main Physics Questions
- In a hydrogen like atom, when an electron jumps from the $M$ - shell to the $L$ - shell, the wavelength of emitted radiation is $\lambda$. If an electron jumps from $N$-shell to the $L$-shell, the wavelength of emitted radiation will be :
- Two masses $m$ and $\frac{m}{2}$ are connected at the two ends of a massless rigid rod of length $l$. The rod is suspended by a thin wire of torsional constant $k$ at the centre of mass of the rod-mass system(see figure). Because of torsional constant $k$, the restoring torque is $\tau =k\theta$ for angular displacement $\theta$. If the rod is rota ted by $\theta_0$ and released, the tension in it when it passes through its mean position will be:
A black body is at a temperature of 2880 K. The energy of radiation emitted by this body with wavelength between 499 nm and 500 nm is U1, between 999 nm and 1000 nm is U2 and between 1499 nm and 1500 nm is U3. The Wien's constant, b = 2.88×106 nm-K. Then,
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Top JEE Main Units and measurement Questions
- A huge circular arc of length 4.4 ly subtends an angle '4s' at the centre of the circle. How long it would take for a body to complete 4 revolution if its speed is 8 AU per second ?
Given: 1 ly = \(9.46 \times 10^{15}\) m
1 AU = \(1.5 \times 10^{11}\) m A vernier caliper has \(10\) main scale divisions coinciding with \(11\) vernier scale division equals \(5\) \(mm\). the least count of the device is :
- Match List-I with List-II.
\[ \begin{array}{|c|c|c|} \hline \text{List-I} & & \text{List-II} \\ \hline \text{A. Coefficient of viscosity} & & \text{I.} \; [M L^2 T^{-2}] \\ \text{B. Surface Tension} & & \text{II.} \; [M L^2 T^{-1}] \\ \text{C. Angular momentum} & & \text{III.} \; [M L^1 T^{-1}] \\ \text{D. Rotational kinetic energy} & & \text{IV.} \; [M L^0 T^{-2}] \\ \hline \end{array} \] - Given below are two statements : one is labelled as Assertion(A) and the other is labelled as Reason (R).
Assertion (A) : In Vernier calliper if positive zero error exists, then while taking measurements, the reading taken will be more than the actual reading.
Reason (R) : The zero error in Vernier Calliper might have happened due to manufacturing defect or due to rough handling.
In the light of the above statements, choose the correct answer from the options given below : - 10 divisions on the main scale of a Vernier calliper coincide with 11 divisions on the Vernier scale. If each division on the main scale is of 5 units, the least count of the instrument is :
Top JEE Main Questions
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What will be the equilibrium constant of the given reaction carried out in a \(5 \,L\) vessel and having equilibrium amounts of \(A_2\) and \(A\) as \(0.5\) mole and \(2 \times 10^{-6}\) mole respectively?
The reaction : \(A_2 \rightleftharpoons 2A\)- The value of is
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Concepts Used:
Units and Measurement
Unit:
A unit of a physical quantity is an arbitrarily chosen standard that is broadly acknowledged by the society and in terms of which other quantities of similar nature may be measured.
Measurement:
The process of measurement is basically a comparison process. To measure a physical quantity, we have to find out how many times a standard amount of that physical quantity is present in the quantity being measured. The number thus obtained is known as the magnitude and the standard chosen is called the unit of the physical quantity.
Read More: Fundamental and Derived Units of Measurement
System of Units:
- CGS system
- FPS system
- MKS system
- SI units
Types of Units:
Fundamental Units -
The units defined for the fundamental quantities are called fundamental units.
Derived Units -
The units of all other physical quantities which are derived from the fundamental units are called the derived units.