Answer:

The capacity of a pure capacitor is given as 1 Farad. In a DC circuit, the effective resistance of the capacitor can be determined by considering its behavior in the circuit. Let's analyze the options given:

1. Zero resistance
2. Infinite resistance
3. 1 ohm
4. 1/2 ohm

Understanding Capacitors:
Before we proceed, it is important to understand the behavior of a capacitor in a DC circuit. A capacitor stores electrical energy in the form of an electric field between its plates. When a voltage is applied across the capacitor, it charges up and stores energy. However, in a DC circuit, once the capacitor is fully charged, it behaves as an open circuit, blocking the flow of current.

Effective Resistance of a Capacitor:
The effective resistance of a capacitor can be determined by considering the time it takes to charge and discharge. In a DC circuit, the capacitor charges up to its maximum voltage and then behaves as an open circuit. As a result, the current through the capacitor becomes zero after it is fully charged.

Since the current is zero, the resistance is infinite. This means that option (2) - infinite resistance is the correct answer.

Conclusion:
In a DC circuit, the effective resistance of a pure capacitor with a capacity of 1 Farad is infinite. After being fully charged, it behaves as an open circuit, blocking the flow of current.

(2) infinite..
as frequency of DC is zero