Physics

The temperature of the black body as calculated from the graph is (Wien's constant = $2.89*{10}^{-3}$ )

A circular beam of light of diameter d=2cm falls on a plane surface of glass. The angle of incidence is 60⁰ and refractive index of glass is $\mu =3/2$ . The diameter of the refracted beam is:

A capacitor is of capacity $C$ and reactance $X$ . If capacitance and frequency become triple then reactance will be

If a diamagnetic substance is brought near the north or the south pole of a bar magnet, it is

A fish looking up through the water sees the outside world contained in a circular horizon. If the refractive index of water is $4/3$ and the fish is 12cm  below the surface of water, the radius of the circle in centimeter is:

At which of the following temperatures does any gas have average molecular kinetic energy double that of at ${20}^{0}C$ ?

A cannot engine works as a refrigerator between $250K$ and $300K$ . It receives $500cal$ heat from the reservoir at the lower temperature. The amount of work done in each cycle to operate the refrigerator is nearly

An object of mass $m$ is connected to a wire of length $\text{'}l\text{'}$ , radius $\text{'}r\text{'}$ and Young's modulus $\text{'}Y\text{'}$ as shown in figure. If the object is released from the horizontal position of the wire, then find out the maximum increment in length of the wire.

An alternating potential V=V₀ sin wt is applied across a circuit. As a result the current I=I₀ Sin $I=I_0 sin \left(\omega t-\frac{\pi }{2}\right)$  flows in it. The power consumed in the circuit per cycle is

A $120kg$ dolphin decelerates from $15m/s$ to $7.5m/s$ in $5s$ to join another dolphin in play. What average force was exerted to slow the first dolphin if it was moving horizontally? (Assume that gravitational force is balanced by the buoyant force of the water)