Independent voltage and current sources - pspice

The symbol of an independent voltage source is V, and the general form for assigning dc and transient value is
V (Name) N+ N- [DC (value)]
+ [(transient value)]
+ [PULSE] [SIN] [EXP] [PWL] [SFFM] [source arguments]
[Note:-The first column with +(plus) signifies continuation of the P Spice statement .After the + sign, the statement can continue in any column.]
N+ is the positive node, and N- is the negative node as shown in the above fig(a),. Positive current flows from node N+ through the voltage source to the negative node N- .
The voltage source need not be grounded. For the dc and transient values, the default value is zero. None or all of the dc and transient values may be specified.
A source can be assigned either a dc value or a transient value. The source is set to the dc value in dc analysis. The time dependent source (e,g,.PULSE,EXP, or SIN) is specified for transient analysis. A voltage source may be used as an Ammeter in P Spice by inserting a zero-valued voltage source in to the circuit for the purpose of measuring current.
Typical Statements
V1 15 0 6V
V2 15 0 DC 6V
VPULSE 10 0 PULSE (0 1 2NS 2NS 2NS 50NS 100NS)
VIN 12 3 DC 15V SIN (0 2V 10KHZ)


INDEPENDENT CURRENT SOURCE
The symbol of an independent current source is I, and the general form for assigning dc and transient value is
I(Name) N+ N- [DC (value)]
+ [(transient value)]
+ [PULSE] [SIN] [EXP] [PWL] [SFFM] [source arguments]
N+ is the positive node, and N- is the negative node as shown in the above fig(b),. Positive current flows from node N+ through the current source to the negative node N- .
The current source need not be grounded. The source specifications are similar to those for independent voltage sources.
Typical Statements
I1 15 0 2MA
I2 15 0 DC 2MA
IPULSE 10 0 PULSE (0 1V 2NS 2NS 2NS 50NS 100NS)
IIN 22 22 DC 2 SIN(0 2V 10KHZ)