# A body of mass ‘ $m$ ‘ is tied to one end of a spring and whirled round in a horizontal plane with a constant angular velocity. The elongation in the spring is $1 \mathrm{~cm}$. If the angular velocity is doubled, the elongation in the spring is $5 \mathrm{~cm}$. The original length of the spring is:

Question:

A body of mass ‘ $m$ ‘ is tied to one end of a spring and whirled round in a horizontal plane with a constant angular velocity. The elongation in the spring is $1 \mathrm{~cm}$. If the angular velocity is doubled, the elongation in the spring is $5 \mathrm{~cm}$. The original length of the spring is:

1. $15 \mathrm{~cm}$

2. $12 \mathrm{~cm}$

3. $16 \mathrm{~cm}$

4. $10 \mathrm{~cm}$

JEE Main Previous Year Single Correct Question of JEE Main from Physics Laws of Motion chapter.

JEE Main Previous Year April 23, 2013

Correct Option: 1

Solution:

(1)

### Related Questions

• The density of a material in SI unit is $128 \mathrm{~kg} \mathrm{~m}^{-3} .$ In certain units in which the unit of length is $25 \mathrm{~cm}$ and the unit of mass is $50 \mathrm{~g}$, the numerical value of density of the material is:

View Solution

• A metal sample carrying a current along $X$-axis with density $J_{x}$ is subjected to a magnetic field $\mathrm{B}_{\mathrm{z}}$ (along z-axis). The electric field $E_{y}$ developed along Y-axis is directly proportional to $J_{x}$ as well as $\mathrm{B}_{Z}$. The constant of proportionality has SI unit

View Solution

• The quantities $x=\frac{1}{\sqrt{\mu_{0} \varepsilon_{0}}}, y=\frac{E}{B}$ and $z=\frac{1}{C R}$ are defined where $C$-capacitance, $R$-Resistance, $l$-length, $E$-Electric field, $B$-magnetic field and $\varepsilon_{0}, \mu_{0},-$ free space permittivity and permeability respectively. Then :

View Solution

• Dimensional formula for thermal conductivity is (here $K$ denotes the temperature:

View Solution

• Dimensional formula for thermal conductivity is (here $K$ denotes the temperature:

View Solution

• A quantity $x$ is given by $\left(I F v^{2} / W L^{4}\right)$ in terms of moment of inertia $I$, force $F$, velocity $v$, work $W$ and Length $L$. The dimensional formula for $x$ is same as that of :

View Solution

• Amount of solar energy received on the earth’s surface per unit area per unit time is defined a solar constant. Dimension of solar constant is:

View Solution

• If speed $\mathrm{V}$, area $\mathrm{A}$ and force $\mathrm{F}$ are chosen as fundamental units, then the dimension of Young’s modulus will be :

View Solution

• If momentum (P), area (A) and time (T) are taken to be the fundamental quantities then the dimensional formula for energy is:

View Solution

• Which of the following combinations has the dimension of electrical resistance $\left(\epsilon_{0}\right.$ is the permittivity of vacuum and $\mu_{o}$ is the permeability of vacuum)?

View Solution

error: Content is protected !!