Exa-3.4(a)   
The cutoff wavelength of the tungsten metal is 274.336nm
  
 Exa-3.4(b)   
The max value of kinetic energy is 1.743 eV
 
 Exa-3.4(c)   
The numerical value of the max kinetic energy is same as stopping potential in volts.Hence 1.74 V