Skip to content

Course home

Sign up

Computational thinking

EasyMediumHard
1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677
Question 4

A digital logic circuit controls a safety valve in a chemical processing unit. The circuit has two binary inputs:

  • XXX, representing whether the pressure is within safe limits (1=True1 = \text{True}1=True, 0=False0 = \text{False}0=False)
  • YYY, representing whether the temperature is within safe limits (1=True1 = \text{True}1=True, 0=False0 = \text{False}0=False)

The safety valve is open when the output signal S S\,S is 1. The logic governing the output is:

S=NOT(X OR NOT Y) S = \text{NOT}(X \text{ OR } \text{NOT } Y) S=NOT(X OR NOT Y)

Complete the truth table for this control system by finding the values of PPP, QQQ, RRR, and SSS.

XXXYYYNOT(X OR NOT Y)\text{NOT}(X \text{ OR } \text{NOT } Y)NOT(X OR NOT Y)
00[ P ]
0[ Q ]1
[ R ]10
10[ S ]
[4]
Markscheme

Computational thinking Questions

  1. GCSE
  2. /Computer Science
  3. /Computational thinking

Question bank