PHYSICS 1260 EXAM 2 QUESTIONS WITH VERIFIED ANSWERS

PHYSICS 1260 EXAM 2 QUESTIONS WITH VERIFIED ANSWERS



When two lamps are connected in SERIES to a battery, the electrical resistance that the
battery "senses" is
A) more than the resistance of either lamp.
B) less than the resistance of either lamp.
C) [none of these] - Answers - A) more than the resistance of either lamp.

SERIES: Req = R1 + R2

*Req (equivalence) goes up, then the I (current) goes down*

When two lamps are connected in PARALLEL to a battery, the electrical resistance that
the battery "senses" is
A) more than the resistance of either lamp.
B) less than the resistance of either lamp.
C) [none of these] - Answers - B) less than the resistance of either lamp.

PARALLEL: Req = (1/R1 + 1/22)^-1
*Req (equivalence) goes down, then the I (current) goes up*

On some early automobiles both headlights failed when one bulb burned out. The
headlights were likely connected in
A) parallel.
B) perpendicular.
C) series.
D) haste. - Answers - C) series.

*Visual- look back at Chpt. 20 notes*
If one resistor is lost in parallel, the circuit will not work for either bulb but if it is in series,
only one headlight will fail.

Magnet A has twice the magnetic field strength of Magnet B and at a certain distance
pulls on magnet B with a force of 100 N. The amount of force that magnet A exerts on
magnet B is
A) at or about 50 N.
B) exactly 100 N.
C) [need more information] - Answers - B) exactly 100 N.

Newton's 3rd law applies.

Compared to the huge force that attracts an iron tack to a strong magnet, the force that
the tack exerts on the magnet is
A) relatively small.