An air bubble in water $$\left(\mu=\frac{4}{3}\right)$$ is shown in figure. The apparent depth of the image of the bubble in plane mirror viewed by observer is.
A transistor is connected in CE configuration. The collector supply is $$10 \mathrm{~V}$$ and the voltage drop across a resistor of $$1000 \Omega$$ in the collector circuit is $$0.5 \mathrm{~V}$$. If the current gain factor is 0.96 , then the base current is
One end of the string of length $l$ is connected to a particle of mass $$m$$ and the other end is connected to a small peg on a smooth horizontal table. If the particle moves in circle with speed $$v$$, the net force on the particle (directed towards centre) will be ( $$T$$ represents the tension in the string)
A thin circular ring of mass ,$$M$$ and radius $$R$$ rotates about an axis through its centre and perpendicular to its plane, with a constant angular velocity $$\omega$$. Four small spheres each of mass $$m$$ (negligible radius) are kept gently to the opposite ends of two mutually perpendicular diameters of the ring. The new angular velocity of the ring will be