If the mass of the bob in a simple pendulum is increased to thrice its original mass and its length is made half its original length, then the new time period of oscillation is $$\frac{x}{2}$$ times its original time period. Then the value of $$x$$ is:
The minimum energy required to launch a satellite of mass $$m$$ from the surface of earth of mass $$M$$ and radius $$R$$ in a circular orbit at an altitude of $$2 R$$ from the surface of the earth is:
A sheet is placed on a horizontal surface in front of a strong magnetic pole. A force is needed to:
A. hold the sheet there if it is magnetic.
B. hold the sheet there if it is non-magnetic.
C. move the sheet away from the pole with uniform velocity if it is conducting.
D. move the sheet away from the pole with uniform velocity if it is both, non-conducting and non-polar.
Choose the correct statement(s) from the options given below:
A $$10 \mu \mathrm{F}$$ capacitor is connected to a $$210 \mathrm{~V}, 50 \mathrm{~Hz}$$ source as shown in figure. The peak current in the circuit is nearly $$(\pi=3.14)$$ :