Question:
A mass of $10 \mathrm{~kg}$ is suspended by a rope of length $4 \mathrm{~m}$, from the ceiling. A force $\mathrm{F}$ is applied horizontally at the midpoint of the rope such that the top half of the rope makes an angle of $45^{\circ}$ with the vertical. Then $F$ equals:
(Take $g=10 \mathrm{~ms}^{-2}$ and the rope to be massless)
$100 \mathrm{~N}$
$90 \mathrm{~N}$
$70 \mathrm{~N}$
$75 \mathrm{~N}$
Question of from chapter.
JEE Main Previous Year 7 Jan. 2020
Correct Option: 1
Solution:
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:
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
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 :
Dimensional formula for thermal conductivity is (here $K$ denotes the temperature:
Dimensional formula for thermal conductivity is (here $K$ denotes the temperature:
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 :
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:
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 :
If momentum (P), area (A) and time (T) are taken to be the fundamental quantities then the dimensional formula for energy is:
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)?