Question

1.1 You have two solenoids with identical cross-sections and lengths. But solenoid #1 has density of turns twice as big as solenoid #2. We can conclude that inductance of solenoid #1 is:

a.   Twice as big as inductance of solenoid #2

b.   Four times as big as inductance of solenoid #2

c.   Same as inductance of solenoid #2

d.   Half of inductance of solenoid #2

e.   Quarter of inductance of solenoid #2.

1.2  You have two solenoids of the same length, same density of turns, but solenoid #2 has twice the diameter of solenoid #1. We can conclude that inductance of solenoid #1 is

a.   Twice as big as inductance of solenoid #2

b.   Four times as big as inductance of solenoid #2

c.   Same as inductance of solenoid #2

d.   Half of inductance of solenoid #2

e.   Quarter of inductance of solenoid #2.

1.3   You have two solenoids of the same diameter, same density of turns, but solenoid #1 is twice as long as solenoid #2. We can conclude that inductance of solenoid #1 is

a.   Twice as big as inductance of solenoid #2

b.   Four times as big as inductance of solenoid #2

c.   Same as inductance of solenoid #2

d.   Half of inductance of solenoid #2

e.   Quarter of inductance of solenoid #2.

1.4 You have two solenoids of the same lengths, diameter and density of turns. But current through solenoid #1 is twice as big as current through solenoid #2. We can conclude that inductance of solenoid #1 is:

a.   Twice as big as inductance of solenoid #2

b.   Four times as big as inductance of solenoid #2

c.   Same as inductance of solenoid #2

d.   Half of inductance of solenoid #2

e.   Quarter of inductance of solenoid #2.

1.5.   You have two solenoids of the same length and diameter. Solenoid #1 has twice density of turns as solenoid #2, and twice current of solenoid #2  flows through solenoid #1 . We can conclude that energy stored is solenoid #1 is

a.   Twice energy as in solenoid #2

b.   Fours times energy as in solenoid #2

c.   Eight times energy as in solenoid #2

d.   16 times energy as in solenoid #2

e.   Same energy is stored in both solenoids.

Answer 1

Inductance of solenoid is given by

where A- area of cross section ; l - length of solenoid ; n - density of turns

Answer 1.1=> b.   Four times as big as inductance of solenoid #2

if n is twice for solenoid #1 then his inductace will be four times solenoid #2.

Answer 1.2=> e.   Quarter of inductance of solenoid #2.

Inductance is directly proportional to the square of diameter.

Answer 1.3=> a.   Twice as big as inductance of solenoid #2

Inductance is directly proportional to the length.

Answer 1.4=> c.   Same as inductance of solenoid #2

Inductance does not depends on current.

Answer 1.5=> d.   16 times energy as in solenoid #2

energy stored in solenoid is given by

twice density and twice current will results in 16 times increse in energy stored.