Physics MCQs
Topic Notes: Physics
MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.
Plato
- Biography: Ancient Greek philosopher (427–347 BCE), student of Socrates and teacher of Aristotle, founder of the Academy in Athens.
- Important Ideas:
- Theory of Forms
- Philosopher-King
- Ideal State
1
Which components are essential to the construction of a cathode ray oscilloscope?
Answer:
all of above
A cathode ray oscilloscope (CRO) functions by using an electron gun to produce a beam of electrons, deflecting plates to steer the beam according to input signals, and a fluorescent screen to visualize the electron path as a waveform.
2
Which instrument is capable of measuring potential difference without drawing current from the circuit?
Answer:
cathode ray oscilloscope (CRO)
A cathode ray oscilloscope (CRO) has an extremely high input impedance. Because of this, it draws negligible current from the circuit under test, allowing it to measure voltage without disturbing the circuit's operation. In contrast, traditional voltmeters have finite resistance and draw some current, which can affect the measurement in high-impedance circuits.
3
Which electronic instrument is commonly utilized to visualize the waveform of sound signals?
Answer:
oscilloscope
An oscilloscope is a laboratory instrument that displays and analyzes the waveform of electronic signals. By using a microphone to convert sound waves into electrical voltage variations, an oscilloscope can graphically represent these signals, allowing us to 'see' the frequency, amplitude, and shape of sound waves.
4
Identify the instrument designed to visualize the magnitude and waveform of time-varying electric currents or potentials.
Answer:
cathode-ray oscilloscope
A cathode-ray oscilloscope (CRO) is a laboratory instrument used to display and analyze the waveform of electronic signals. It plots the voltage of a signal against time, allowing for the observation of changing electrical potentials.
5
When connecting a voltmeter to a circuit, to which terminal of the battery should the voltmeter's negative terminal be connected?
Answer:
negative terminal
To ensure correct polarity readings on an analog voltmeter, the negative terminal of the meter must be connected to the negative terminal of the source or the lower potential point in the circuit. Connecting it to the positive terminal would result in a reverse deflection of the needle.
6
Which instrument is commonly utilized to visualize electrical waveforms, such as heartbeats, and to measure voltage signals over time?
Answer:
cathode-ray oscilloscope
A cathode-ray oscilloscope (CRO) is a laboratory instrument used to display and analyze the waveform of electronic signals. By plotting voltage against time, it allows for the visual representation of periodic signals, such as those generated by cardiac activity in medical monitoring, making it an essential tool in both physics and biomedical engineering.
7
What are the primary components that constitute a standard cathode-ray oscilloscope?
Answer:
all of above
A cathode-ray oscilloscope (CRO) functions by using an electron gun to produce a beam, deflecting plates to steer the beam based on input signals, and a fluorescent screen to visualize the resulting waveform. Therefore, all listed components are essential.
8
Which type of wave is typically visualized using an oscilloscope?
Answer:
sound
An oscilloscope is an electronic test instrument that displays varying signal voltages as a two-dimensional plot. It is commonly used to visualize sound waves by converting acoustic pressure variations into electrical signals via a microphone.
9
What components are typically included in a standard multimeter?
Answer:
Voltmeter, Currentmeter & Ohm meter
A multimeter is an electronic measuring instrument that combines several measurement functions in one unit. A standard multimeter can measure voltage (voltmeter), current (ammeter), and resistance (ohmmeter), making it an essential tool for electrical diagnostics and circuit testing.
10
In a Cathode Ray Oscilloscope (C.R.O), what type of potential is applied to the control grid?
Answer:
negative potential
In a C.R.O., the control grid is maintained at a negative potential relative to the cathode. This negative bias serves to regulate the flow of electrons from the cathode, thereby controlling the intensity or brightness of the electron beam as it hits the fluorescent screen.