Answer:
Explanation:
Concave lens also called as diverging lens i.e. it diverges ray of light coming towards it.
Concave lens is thicker at the edges and thinner at the center.
Concave lens formed the virtual image of the object i.e. it cannot be trace on screen. This lens is used to treat the nearsightedness or myopia in which a person is unable to see the far object clearly.
Answer: The given statement is false.
Explanation:
Lightening is defined as steady expansion of air within and surrounding path due to the sudden increase in pressure and temperature that leads to emission of lightning.
Basically, lightning is a state of plasma in which the molecules are very rapidly striking with each other as it also contains positively charged ions and negatively charged electrons.
Lightning always leads to the production of thunder.
Therefore, we can conclude that the statement not every lightning strike produces thunder, is false.
4) They have non-moving magnetic fields.
Answer:
The objects become oppositely charged and have equal amounts of charge.
Explanation:
There are three methods for charging objects:
- Conduction: a charged object is brought in contact with a neutral object. Electrons are transferred from the charged object to the neutral one, which also becomes charged
- Induction: a charged object is brought close (but not in contact) to a neutral object. The charges inside the neutral object redistribute, such that those of opposite sign to the charge in the charged object migrate on the side closer to the charged object, while the charges of same sign migrate towards the opposite side. If the neutral object is then grounded, the charges on the opposite side flow to the ground, leaving the neutral object charged as well
- Friction: two objects initially neutral are rubbed against each other. Electrons move from one object to the other one: therefore, one object becomes positively charged while the other one becomes negatively charged. Since the charge gained by one object is equal to charge lost by the other object, it follows that the two objects have same magnitude of charge, but with opposite sign.
