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Let a source of alternating e.m.f. $\text{E} = \text{E}_\circ\sin\omega\text{t}$ be connected to a capacitor of capacitance C. If 'I' is the instantaneous value of current in the circuit at instant t, then $\text{I}=\frac{\text{E}_0}{\frac{1}{\omega\text{C}}}\sin\Big(\omega\text{t}+\frac{\pi}{2}\Big).$ The capacitive reactance limits the amplitude of current in a purely capacitive circuit and it is given by $\text{X}_\text{C}=\frac{1}{\omega\text{C}}.$

1. What is the unit of capacitive reactance?

1. Farad
2. Ampere
3. Ohm
4. Ohm^-1

2. The capacitive reactance of a $5\mu\text{F}$ capacitor for a frequency of 10⁶Hz is:

1. $0.032\Omega$
   
2. $2.52\Omega$
   
3. $1.25\Omega$
   
4. $4.51\Omega$
   

3. In a capacitive circuit, resistance to the flow of current is offered by:

1. Resistor
2. Capacitor
3. Inducto
4. Frequency

4. In a capacitive circuit, by what value of phase angle does alternating current leads the e.m.f?

1. 45º
2. 90º
3. 75º
4. 60º

5. One microfarad capacitor is joined to a 200V, 50Hz alternator. The rrns current through capacitor is:

1. 6.28 × 10^-2A
2. 7.5 × 10^-4A
3. 10.52 × 10^-2A
4. 15.25 × 10^-2A