Current Electricity — Physics STD 12 Science — Question

A string clamped at both ends vibrates in its fundamental mode. Is there any position (except the ends) on the string which can be touched without disturbing the motion? What if the string vibrates in its first overtone?

Galileo was punished by the Church for teaching that the sun is stationary and the earth moves around it. His opponents held the view that the earth is stationary and the sun moves around it. If the absolute motion has no meaning, are the two, viewpoints not equally correct or equally wrong?

A charge 'q' is placed at the centre of a cube of side l.What is the electric flux passing through each face of the cube?

Answer the following questions:
Magnetic field lines are always nearly normal to the surface of a ferromagnet at every point. (This fact is analogous to the static electric field lines being normal to the surface of a conductor at every point.) Why?

What is the electric flux through a cube of side 1 cm which encloses an electric dipole?

What will be the path of a charged particle moving along the direction of a uniform magnetic field?

What is called nuclear reaction?

Mark the correct options.

1. Luminous flux and radiant flux have same dimensions.
2. Luminous flux and luminous intensity have same dimensions.
3. Radiant flux and power have same dimensions.
4. Relative luminosity is a dimensionless quantity.

If length of a wire of resistivity p is stretched to three times, then what will be new resistivity?