Test your fundamental knowledge of logic gates, their functions, and basic applications in digital circuits. This quiz helps reinforce essential concepts related to AND, OR, NOT, NAND, NOR, and XOR gates through practical examples and scenarios.
Which logic gate outputs HIGH (1) only when all its inputs are HIGH, for example, when both inputs A=1 and B=1?
Explanation: An AND gate requires all inputs to be HIGH to produce a HIGH output, which fits the described behavior. OR and XOR gates can produce HIGH with just one input being HIGH, so they are incorrect. The NOT gate is a single-input inverter, irrelevant to this two-input scenario.
If you want a circuit output to be HIGH (1) whenever at least one input is HIGH, which logic gate should you use?
Explanation: An OR gate outputs HIGH when any of its inputs are HIGH, matching the requirement in the question. AND needs all inputs HIGH, so it's too restrictive. 'NUT' is a typo and not a logic gate. NOR outputs HIGH only when all inputs are LOW, which is the opposite behavior.
Which logic gate inverts its single input, turning a LOW (0) into HIGH (1) and vice versa?
Explanation: A NOT gate, also known as an inverter, produces the opposite value of its single input. AND and XOR gates are multi-input operators, not inverters. 'SAN' is a misspelling and does not represent any logic gate.
When both inputs of a NAND gate are HIGH (1), what is the output?
Explanation: A NAND gate outputs LOW only when all its inputs are HIGH; otherwise, it outputs HIGH. 'HIGH' would be correct for an AND gate, but not for NAND. 'NEUTRAL' and 'FLOAT' are not valid logic levels in this context.
Which gate outputs HIGH (1) only if all its inputs are LOW (0), making it useful for detecting when none of several conditions are met?
Explanation: A NOR gate inverts the output of an OR gate, so it outputs HIGH only when all inputs are LOW. XOR outputs HIGH if an odd number of inputs are HIGH. AND and OR do not fit this behavior, as they do not invert their outputs.
Which logic gate outputs HIGH (1) only when an odd number of its inputs are HIGH, such as A=1 and B=0 or A=0 and B=1?
Explanation: The XOR (exclusive OR) gate produces HIGH output only if the number of HIGH inputs is odd, which distinguishes it from the others. NAND and AND do not behave this way. 'OLF' is a typo and does not represent a logic gate.
If you want an alarm to sound when either of two doors is open, which gate should connect the door sensors to the alarm?
Explanation: An OR gate ensures the alarm sounds when either input (door sensor) is triggered. AND would only alarm if both doors were open. NOT is not suitable for combining two signals, and NOR would activate only when both doors are closed.
Which gate would best be used to invert a digital signal, such as turning a HIGH input signal into a LOW output?
Explanation: The NOT gate, or inverter, outputs the opposite of its input, which is exactly the desired effect. AND and NOR require multiple inputs and serve different functions. XOR only inverts if one input is HIGH and the other is LOW, not for a single input inversion.
If an output is required to be HIGH only when both inputs are NOT HIGH, which combination of gates could achieve this function?
Explanation: A NOR gate—formed by passing the output of an OR gate through a NOT gate—output HIGH when both inputs are LOW. NAND and XOR do not provide the required output, and AND alone cannot invert signals or check for 'not HIGH'.
If a lamp is to light up only when exactly one of two switches is ON, which gate should be used?
Explanation: The XOR gate provides a HIGH output when exactly one of its two inputs is HIGH, which is ideal for this scenario. AND would require both switches to be ON. NOR and NOT do not fit the requirement of detecting 'exactly one ON'.