A 20 watt, 50 V lamp is connected in series to a.c. mains of 250 V, 50 Hz. Calculate to value of capacitor to run the lamp.

A 6 V - 12 W lamp is connected in series with a source of 12 V supply. Calculate the value of the resistance R for the proper working of the lamp. What is the current flowing through the circuit ?

A 50 W, 100V lamp is to be connected to an ac mains of 200V, 50 Hz. What capacitor is essential to be put in series with the lamp?

A capacitor of 100 muF , a resistor of 20 Omega and an inductor of inductance L are connected in series with an a.c. source of frequency 50 Hz. Calculate the value of inductance L of the inductor, if phase angle between current and voltage is zero.

A capacitor and resistor of 12 Omega are connected in series with an AC supply 100 V, 50 Hz . Calculate the capacitance of the capacitor if power factor of the RC circuit is 0.8.

A 20 volts 5 watt lamp is used in ac main of 220 volts 50 c.p.s. Calculate the (i) Capacitance of capacitor. (ii) Inductance of inductor, to be put in series to run the lamp, (iii) What pure resistance should be included in place of the above device so that the lamp can run on its voltage. (iv) Which of the above arrangements will be more economical and why ?

A 20 V - 5 W lamp is to run on 200 V- 50 Hz a.c. mains. Find the capacitance of a capacitor required to run the lamp.

A 50 Omega resistor is connected in series to an inductor and a capacitor to an AC source 220 V , 50 Hz . Calculate the value of inductance and capacitance if voltages across resistor inductor and capacitor are 75 V , 210 V and 420 V respectively.