Phys 202- Exam 1 updated questions and
CORRECT answers
Two charged balls are
repelling each other as
they hang from the
ceiling. What can you
say about their
charges? - CORRECT ANSWER both are positive or both are negative
When you rub a plastic rod with fur, the
plastic rod becomes negatively charged
and the fur becomes positively
charged. As a consequence of rubbing
the rod with the fur, - CORRECT ANSWER the rod gains mass and the fur loses mass
When we say charge is conserved,
we mean that charge can - CORRECT ANSWER only be transferred from one place to
another
conductor - CORRECT ANSWER A material whose
conduction electrons are free to move
throughout. Metals are good
conductors.
insulator - CORRECT ANSWER A material whose electrons
rarely move from atom to atom.
Most insulators
are non-metals
, A metal ball hangs from
the ceiling by an
insulating thread. The
ball is attracted to a
positive-charged rod held
near the ball. The charge
of the ball must be: - CORRECT ANSWER negative or neutral
What is the magnitude of the
force F2? (F1 is 3N) - CORRECT ANSWER The force of one on the other
of a pair is the same as the reverse F2 is 3N
If we increase one charge to 4Q,
what is the magnitude of F1? (F1 is 3N) - CORRECT ANSWER F1 = k(4Q)(Q)/r2 so
magnitude of F1 is 12N
Two balls with charges +Q and +4Q are
fixed at a separation distance of 3R. Is it
possible to place another charged ball Q0
on the line between the two charges such
that the net force on Q0 will be zero? - CORRECT ANSWER yes, independent of the
sign
(or value) of Q0 (A positive charge would be repelled by both charges, so a point where
these two repulsive forces cancel
can be found. A negative charge
would be attracted by both, and the
same argument holds.)
CORRECT answers
Two charged balls are
repelling each other as
they hang from the
ceiling. What can you
say about their
charges? - CORRECT ANSWER both are positive or both are negative
When you rub a plastic rod with fur, the
plastic rod becomes negatively charged
and the fur becomes positively
charged. As a consequence of rubbing
the rod with the fur, - CORRECT ANSWER the rod gains mass and the fur loses mass
When we say charge is conserved,
we mean that charge can - CORRECT ANSWER only be transferred from one place to
another
conductor - CORRECT ANSWER A material whose
conduction electrons are free to move
throughout. Metals are good
conductors.
insulator - CORRECT ANSWER A material whose electrons
rarely move from atom to atom.
Most insulators
are non-metals
, A metal ball hangs from
the ceiling by an
insulating thread. The
ball is attracted to a
positive-charged rod held
near the ball. The charge
of the ball must be: - CORRECT ANSWER negative or neutral
What is the magnitude of the
force F2? (F1 is 3N) - CORRECT ANSWER The force of one on the other
of a pair is the same as the reverse F2 is 3N
If we increase one charge to 4Q,
what is the magnitude of F1? (F1 is 3N) - CORRECT ANSWER F1 = k(4Q)(Q)/r2 so
magnitude of F1 is 12N
Two balls with charges +Q and +4Q are
fixed at a separation distance of 3R. Is it
possible to place another charged ball Q0
on the line between the two charges such
that the net force on Q0 will be zero? - CORRECT ANSWER yes, independent of the
sign
(or value) of Q0 (A positive charge would be repelled by both charges, so a point where
these two repulsive forces cancel
can be found. A negative charge
would be attracted by both, and the
same argument holds.)
