Dw the current waveform of the output resistor rl if vbr

Question

1) Draw the current waveform of the output resistor R_L if V_BR = 20 V, I_H = 20 mA, and R_L = 1000 ohms. Label the current graph with the correct value of the output current. Assume components are ideal and voltage and current are in phase

2) Determine a range of values for R₁ that will be able to turn on/off the UJT if: η= 0.3, I_p = 30 RA, l_v = 40 RA, V_v = 5 V

3) What value will R₃ need to be in order for the SCR to turn off if I_H = 30 mA and V_AK = 0.7 V?