Draw a circuit diagram using the dual control switches to light a staircase electric light and explain its working

Draw the diagram of a dual control switch when the appliance is switched 'ON'.

Explain the dual nature of light.

Draw a circuit diagram of L.E.D. What are its advantages?

Draw a simple diagram of a hydraulic jack and explain its working.

State briefly the underlying principle of a transistor oscillator. Draw a circuit diagram showing how the feedback is accomplished by inductive coupling. Explain the oscillator action.

Draw a labelled circuit diagram of a simple electric motor and explain its working. In what way these simple electric motors are different from commercial motors?

(a) Explain with the help of suitable diagram , the two processes which occur during the formations of a p -n junction diode . Hence , define the terms : (i) depletion region and (ii) potential barrier : (b) Draw a circuit diagram of a p - n junction diode under forward bias and explain its working .

Explain the formation of depletion layer and potential barrier in p-n junction. Draw the circuit diagram of a half wave rectifier and explain its working.

Draw a labelled circuit diagram of a potentiometer to measure internal resistance of a cell. Write the working formula. (Derivation not required).

Draw a labelled circuit diagram of a transistor as a switch and draw its input and output graphs.