B. False.
An atom with a positive charge is a cation, not anion.
Answer:a
Explanation:
We have to lift the load two loads up one story, so energy required is
let m be the mass of each load and h is the height of each story
Energy 

Here energy gained is the potential energy which depends upon the datum(floor).
For lifting one load up one story
Energy required

thus
is half of 
So option a is correct
Some of these frictions depend on the Pressure, temperature of atmosphere.
Static Friction: This is the friction force when two objects in contact are not moving relative to each other. This friction is higher than kinetic friction.
Kinetic or Dynamic friction: this the friction force opposing the motion of objects, when two objects in contact are in motion relative to each other. It is less than the static friction. The two surfaces are rubbing against each other as they move.
Rolling friction: This is the friction when two objects are in contact and one object is rolling over the other - like a wheel on a road. The point of contact appears as stationary. The rolling friction is very less compared to static friction & dynamic friction.
Lubricated friction: this is the friction between two solid surfaces in contact with a layer of lubricant fluid flowing in between them. This friction is the least.
Fluid friction - viscosity : this is friction between two adjacent layers that are moving relative to each other at different speeds in a fluid. This is not high.
Internal friction: when an object is compressed and forced to deform, like in a piece of rubber, there is friction between the layers, that opposes this deformation.
Skin friction is the friction that opposes movement of a fluid across a solid surface. This is also called drag. When a coin is dropped in water, there is a friction called drag on the coin. Same is the case when a ball is thrown, a drag is experienced by the ball due to the drag of air.
The correct answer for the question that is being presented above is this one: "D.
Property Electric Field Magnetic Field
<span>Can be produced by moving electric charge X </span>
Have two sides with opposite characteristics X X
Can make metals, such as nickel, iron, and cobalt, into magnets X X
<span>Can be turned on or off with a switch X"</span>