Electronics — Physics STD 12 Science — Question

A concave lens of glass, refractive index 1.5, has both surfaces of same radius of curvature R. On immersion in a medium of refractive index 1.75, it will behave as a(a) Convergent lens of focal length 3.5 R(b) Convergent lens of focal length 3.0 R(c) Divergent lens of focal length 3.5 R(d) Divergent lens of focal length 3.0 R

An inductor of 2 henry and a resistance of 10 ohms are connected in series with a battery of 5 volts. The initial rate of change of current is (a) 0.5 amp/sec(b) 2.0 amp/sec(c) 2.5 amp/sec(d) 0.25 amp/sec

A hollow tube is carrying an electric current along its length distributed uniformly over its surface. The magnetic field:

1. Increases linearly from the axis to the surface.
2. Is constant inside the tube.
3. Is zero at the axis.
4. Is zero just outside the tube.

Isoclinic lines are the lines joining places with:

The range of wavelength of the visible light is(a) 10 Å to 100 Å(b) 4,000 Å to 8,000 Å(c) 8,000 Å to 10,000 Å(d) 10,000 Å to 15,000 Å

If light is passed through a double-slit opening and falls onto a screen, Identify the pattern produced on the screen.

Which of the following are non polar molecules:

Essential difference between electrostatic shielding by a conducting shell and magnetostatic shielding is due to:

The dielectric constant of water is :