(1) There are three basic types of dc motors; series, shunt, and compound.
(2) In the series motor, the field windings, consisting of relatively few turns of heavy wire, are connected in series with the armature winding.
Regarding the above statements,
A) only No. 1 is true.
B) both No. 1 and No. 2 are true.
C) only No. 2 is true.

The correct option is C

Explanation:

No. 1 is not true because a Permanent magnet DC motor is also one of the main types of DC motors. A DC motor is any of a class of motors that converts direct current electrical energy into mechanical energy.

C) only No. 2 is true.

Explanation:

There are actually 4 main types of DC motors. Namely Series, Shunt, and Compound and Permanent Magnet DC Motors.

The permanent motor magnet requires a permanent magnet to generate flux of field. This form of DC motor offers excellent initial torque and strong speed control, however power is restricted so they are usually used in applications with low horsepower rates.

a solenoid is created by wrapping a l = 90 m long wire around a hollow tube of diameter d = 4.5 cm.   the wire diameter is d = 0.9 mm.   the solenoid wire is then connected to a power supply so that a current of i = 9 a flows through the wire.

randomized variablesl = 90 m

d = 4.5 cm

d = 0.9 mm

i = 9 a                                          

write an expression for the number of turns, n, in the solenoid. you do not need to take into account the diameter of the wire in this calculation.

calculate the number of turns, n, in the solenoid.

write an expression for the length of the solenoid (l2) in terms of the diameter of the hollow tube d.

calculate the length of the solenoid (l2)   in meters.

calculate the magnitude of the magnetic field at the center of the solenoid in teslas.

explanation:

no

sodium is solid at rt