Amplitude of a mass-spring system, which is executing simple harmonic motion decreases with time. If mass = 500g, Decay constant = 20 g/s then how much time is required for the amplitude of the system to drop to drop to half of its initial value? (ln 2 = 0.693)

For the given circuit, comment on the type of transformer used.

A solid disc of radius 'a' and mass 'm' rolls down without slipping on an inclined plane making an angle $$\theta$$ with the horizontal. The acceleration of the disc will be $${2 \over b}$$g sin$$\theta$$ where b is ____________. (Round off to the Nearest Integer) (g = acceleration due to gravity, $$\theta$$ = angle as shown in figure)

The energy dissipated by a resistor is 10 mJ in 1 s when an electric current of 2 mA flows through it. The resistance is ___________$$\Omega$$. (Round off to the Nearest Integer)