M3 64ช่วยพี่ด้วย

How can mass number of atom be determined

• Number of Protons only
• Number of Electrons and Protons
• Number of Protons and Neutrons
• Number of Neutrons only

How can the size of an atom be determined? Number of Protons and Neutrons.

• Valence Shell. Valence Shell.
• Electron Orbit.
• Number of valence electrons.

What is correct about electromagnetic force between two charged bodies?

• Proportional to the square of the distance between them.
• Inversely proportional to the square of the distance between them.
• Proportional to the distance between them.
• Inversely proportional to the distance between them.

What is correct about charging by conduction?

• It is a charging method when objects are in contact.
• There is no electron transfer between objects.
• There is a flow of protons to negatively charged object in contact
• Positive charge induces negative charge.

What will be the direction of induced current when the current decreases in the coil?

• Opposite direction
• The same direction
• Clockwise
• Counterclockwise

What is the Piezoelectric effect?

• Ability of material to convert electrical energy to mechanical energy.
• Ability of material to generate electrical energy when applied stress.
• Ability of material to generate electrical energy when applied heat.
• Both A and B are correct

Which statement is correct about thermocouple?

• Composed of 2 different metals.
• E.M.F. is generated due to different temperatures between 2 junctions.
• Voltage is measured at cold junctions.
• All of the above.

How the current flow can be increased when producing voltage by magnetism?

• Move the magnet instead of the conductor.
• Place the conductor closer to the magnet.
• Coil the wire.
• All of the above.

Which statement is correct about sulphation?

• The formation of lead sulphate on anode and cathode.
• The formation of lead sulphate on anode.
• Lead peroxide is changed to lead sulphate.
• Sponge lead is changed to sulphate.

What is polarization of the cell?

• Having impurity in anode.
• Having impurity in the cathode.
• Having hydrogen covers the surface of anode and cathode.
• Having hydrogen cover the surface of the cathode.