Direct impact of two smooth sphere

When an electric field is applied to the metal, the free electrons move in ______ direction

Choose all the options which are applications of static electricity.

• Photocopying

• Maglev Trains

• Electric Generators

• Pollution and smoke control from factories

• Painting cars to spread paint evenly

There is no loss of energy and resultant velocity is zero, this indicates ______ of free electrons

• inelastic collision

• elastic collision

• Direct compact

• Oblique impact

The following type of charging involves transfer of charge due to direct contact between two surfaces.

• Charging by Induction

• Charging by Friction

• Charging by Conduction

• Charging by Convection

In DOS, volume of the sphere of radius n is equal to the number of energy states

• volume of cube

• number of energy states

• number of energy levels

• none in the list

A hollow metal sphere of radius 5 cm is charged so that the potential on its surface is 10 V. The potential at the centre of the sphere is?

• 0 V

• 10 V

• Same as at point 5 cm away from the surface

• Same as at point 25 cm away from the surface

A uniformly charged (thin) non-conducting shell (hollow sphere) of radius R with the total positive charge Q is placed at a distance d away from an infinite non-conducting sheet carrying a uniformly distributed positive charge with a density σ. The distance d is measured from shell’s center (point O). What is the magnitude of the total electric field at the center of the shell?

• $\frac{σ}{2ε_0}$

• $\frac{Q}{4πε_0R^2}+\frac{σ}{2ε_0}$

• $\frac{Q}{4πε_0R^2}+\frac{σ}{ε_0}$

• $\frac{σ}{ε_0}$

the basic structural unit or building block of the crystal structure and defines the crystal structure by virtue of its geometry and the atom positions within

• Lattice

• Amorphous

• Unit Cells

• FCC

Cube edge length a or x and the atomic radius R in FCC is related by

• a = 2R√𝟐

• a = $\frac{4R}{\sqrt{3}}$

A wire in the plane of the page carries a current I directed toward the top of the page. If the wire is located in a uniform magnetic field B directed out of the page, what is the direction of the force on the wire resulting from the magnetic field?

• up
• down
• right 
• left