Physics Test 12...

A short linear object of length b lies along the axis of a concave mirror of focal length f at a distance u from the pole of the mirror. The size of the image is approximately equal to:

A gaseous mixture consists of 16 g of helium and 16 g of oxygen. The ratio CP/CV of the mixture is:

A non-conducting disc of radius R, charge q is rotating about an axis passing through its centre and perpendicular to its plane with an angular velocity ω, charge q is uniformly distributed over its surface. The magnetic moment of the disc is:

A thin uniform annular disc (see figure) of mass M has outer radius 4R and inner radius 3R. The work required to take a unit mass from point P on its axis to infinity is:

A body cools in 7 minutes from 60∘C to 40∘C. If the temperature of the surrounding is 10∘C, the temperature after next 7 minutes will be:

An object is placed on the surface of a smooth inclined plane of inclination θ. It takes time t to reach the bottom. If the same object is allowed to slide down a rough inclined plane of inclination θ, it takes time nt to reach the bottom where n is the number greater than one. The coefficient of friction μ is given by:

A circular disc of radius 0.2 meter is placed in a uniform magnetic field of induction  in such a way that its axis makes an angle of 60^∘ with . The magnetic flux linked with the disc is:

Monochromatic radiation of wavelength λ is incident on a hydrogen sample containing ground state. Hydrogen atoms absorb the light and subsequently emit radiations of ten different wavelengths. The value of λ is:

A steady current flows in a metallic conductor of the non-uniform cross-section. The quantity/quantities constant along the length of the conductor is/are:

A massless platform is kept on a light elastic spring, as shown in the figure. When a particle of mass 0.1 kg is dropped on the pan from a height of 0.24 m, the particle strikes the pan, and the spring is compressed by 0.01 m. From what height should the particle be dropped to cause a compression of 0.04 m?