MCQ
The angular velocity of seconds hand of a watch will be
- A$\frac{\pi }{{60}}\ rad/\sec $
- ✓$\frac{\pi }{{30}}\ rad/sec$
- C$60\,\pi \,\,rad/sec$
- D$30\,\pi \,\,rad/sec$
✓
Answer
Correct option: B.
$\frac{\pi }{{30}}\ rad/sec$
b
We know that second's hand completes its revolution $(2p)$ in $60\ sec$
We know that second's hand completes its revolution $(2p)$ in $60\ sec$
$\omega = \frac{\theta }{t} = \frac{{2\pi }}{{60}} = \frac{\pi }{{30}}rad/sec$
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
The amount of heat needed to raise the temperature of $4\, moles$ of a rigid diatomic gas from $0^{\circ} {C}$ to $50^{\circ} {C}$ when no work is done is ......${R}$ ($R$ is the universal gas constant)
→A projectile is projected at $30^{\circ}$ from horizontal with initial velocity $40\,ms ^{-1}$. The velocity of the projectile at $t =2\,s$ from the start will be $........$ (Given $g =10\,m / s ^2$ )
→A steel rod has a radius $10 \,mm$ and a length of $1.0 \,m$. A force stretches it along its length and produces a strain of $0.32 \%$. Young's modulus of the steel is $2.0 \times 10^{11} \,Nm ^{-2}$. What is the magnitude of the force stretching the rod is ........ $kN$
→The rate of loss of heat from a body cooling under conditions of forced convection is proportional to its $(A)$ heat capacity $(B)$ surface area $(C)$ absolute temperature $(D)$ excess of temperature over that of surrounding : state if
→A small solid ball is dropped from a height above the free surface of a liquid. It strikes the surface of the liquid at $t = 0$. The density of the material of the ball is $500\ kg/m^3$ and that of liquid is $1000\ kg/m^3$ If the ball comes momeritariiy at rest at $t = 2\ sec$ then initial height of the ball from surface of liquid was ..... $m$ (neglect viscosity)
→Two masses $m_1$ and $m_2$ ($m_1$ > $m_2$) are connected by massless flexible and inextensible string passed over massless and frictionless pulley. The acceleration of center of mass is
→A body is sliding down an inclined plane (angle of inclination $45^o$). If the coefficient of friction is $0.5$ and $g = 9.8\, m/s^2$. then the acceleration of the body downwards in $m/s^2$ is
→A thin plate separates two liquids of coefficients of viscosity $\eta$ and $4\ \eta$ kept between two fixed plates as shown. If plate has to be pulled by applying minimum force then $\frac{d_2}{d_1}$ is
→In one dimensional motion, instantaneous speed $v$ satisfies $0\le\text{v}<\text{v}_0.$
→A particle is whirled in a vertical circle of radius $1.0\ m$ using a string with one end fixed. If the ratio of maximum and minimum tension in the string is $\frac{5}{3}$, the minimum velocity of the particle during circular motion is ......... $ms^{-1}$
→