Communication — Physics STD 12 Science — Question

A dip circle is taken to geomagnetic equator. The needle is allowed to move in a vertical plane perpendicular to the magnetic meridian. The needle will stay:

Semiconductors are generally made up of which substance?

Between the plates of a parallel plate condenser there is 1mm thick paper of dielectric constant 4. It is charged at 100 volt. The electric field in volt/metre between the plates of the capacitor is(a) 100(b) 100000(c) 25000(d) 4000000

Name a device which is commonly used to convert an electric signal into a visual signal:

Beta particle An unknown particle is being studied in a magnetic field of variable intensity and direction. When the magnetic field is turned off, the particle is observed to move toward the earth. When the magnetic field is turned on, the particle is observed to continue to move toward the earth, no matter the strength or the direction of the magnetic field. Which of the particles listed below is most likely the unknown particle?

The distance between the plates of a parallel plate capacitor is d. A metal plate of thickness d/2 is placed between the plates. The capacitance would then be(a) Unchanged(b) Halved(c) Zero  (d) Doubled

In a diffraction pattern by a wire, on increasing diameter of wire, fringe width(a) Decreases(b) Increases(c) Remains unchanged(d) Increasing or decreasing will depend on wavelength

In a charged capacitor, the energy is stored in: