Question

what are the equations or procedure for the following questions 2.Capacitor wired with a resistor, find the time constant. 3.The magnetic field generated by a current at distance d from the wire, and the directions 4.The magnetic field in a solenoid, 5- The efficiency, number of turns, and the voltages of the transformer 6- The equivalent capacitance in combination. 7- Resistors code. 8- The resonance frequency.

Answer 1

2.

Time constant of a series RC circuit is given as

T = RC

where R = resistance of the resistor , C = capacitance of the capacitor, T = Time constant

3.

The magnetic field generated by a long wire carrying current "i" in it at a distance "d" perpendicular to wire, is given as

B = (_o/4) (2i/d)

direction of magnetic field is determined using right hand curl rule.

4.

magnetic field in a solenoid is given as

B = ni

B = magnetic field , n = number of turns per unit length , i = current in the solenoid

5.

efficiency of transformer is given as

= Output power/Input Power

The relation between number of turns and voltages in a transformer is given as

n_s/n_p = E_s/E_p

n_s = number of turns in secondary

n_p = number of turns in primary

E_s = Voltage in secondary

E_p = Voltage in primary

6.

Equivalent capacitance in parallel combination is given as

C_p = C₁ + C₂ + C₃ + .....

Equivalent capacitance in series combination is given as

1/C_s = 1/C₁ + 1/C₂ + 1/C₃ + .....