Physics Questions Practice Question and Answer
8 Q: A potentiometer is considered a versatile and accurate device to make an electrical measurement of EMF. Why?
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63c8d7f2bdbddb32fda0219d- 1Because the method involves a combinationfalse
- 2There are cells involvedfalse
- 3Because of potential gradientsfalse
- 4As there is no flow of current through the galvanometertrue
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Answer : 4. "As there is no flow of current through the galvanometer"
Explanation :
A potentiometer is an accurate and versatile device to make electrical measurements of emf because the method involves a condition of no current flow through the galvanometer, the device can be used to measure potential difference, internal resistance of a cell and compare emf's of two sources. Q.
Q: Degree of dissociation does not depend on which of the following factors?
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63c7cd09b338bc336f093b86- 1Nature of the solutefalse
- 2Nature of the solventfalse
- 3Soundtrue
- 4Concentrationfalse
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Answer : 3. "Sound "
Explanation :
The Degree of dissociation does not depend on catalyst.The equivalent conductivity of 0.1M weak acid is 100 times less than that at infinite dilution.
Q: What is the degree of dissociation for strong electrolytes?
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63c7ccbc8731ac33279b21f7- 11true
- 20false
- 3Less than 1false
- 4Greater than 1false
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Answer : 1. "1"
Explanation :
Strong electrolytes have a degree of dissociation close to one, while weak electrolytes have a degree of dissociation less than one. Solvent nature: Solvents with a high dielectric constant show more dissociation. Dilution: As the solution is diluted, the degree of dissociation increases.
Q: Polar satellites are used for high-resolution imaging of the earth’s surface because _____
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63c7c166bd6d9033208efbdf- 1They have better camerasfalse
- 2They are very high above the surface of the earth and travel slowly to gather more informationfalse
- 3They are closer to the surface of the earth and can cover vast areas very quicklytrue
- 4They can be launched by most countries in the worldfalse
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Answer : 3. "They are closer to the surface of the earth and can cover vast areas very quickly"
Explanation :
Explanation: Since polar satellites orbit close to the surface of the earth, it is easier to click images of the planet's surface with greater detail. Their high orbital velocity enables them to view most of the surface strip-by-stip very quickly with which high-resolution images can be constructed.
Q: Most waves used for communication purposes rely on geostationary satellites because _____
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63c7baad1c47ef334bdd8984- 1They cannot transmit data at long distances due to curvature of the earthtrue
- 2They are reflected by the atmospherefalse
- 3They are very cheapfalse
- 4It does not occupy space on the earth’s surfacefalse
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Answer : 1. "They cannot transmit data at long distances due to curvature of the earth"
Explanation :
Explanation: Most communication waves cannot transmit data accurately over long distances due to the curvature of the earth. They can only do so in the line of sight. However, they are not reflected by the ionosphere like radio waves and can be relayed to a wide area using geostationary satellites.
Q: If the kinetic energy of a satellite is halved, its orbital radius becomes _____
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63c7b9788731ac33279af158- 1½ timestrue
- 22 timesfalse
- 34 timesfalse
- 4Infinityfalse
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Answer : 1. "½ times"
Explanation :
radius of its orbit will become half.
Q: What are the conditions for gas like Carbon monoxide to obey the ideal gas laws?
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63c8f745bdbddb32fda0e8d0- 1Low temperature and low pressurefalse
- 2Low temperature and high pressurefalse
- 3High temperature and low pressuretrue
- 4High temperature and high pressurefalse
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Answer : 3. "High temperature and low pressure "
Explanation :
A real gas can behave as an ideal gas if volume of molecule is negligible and interaction between molecule is negligible. This will happen if number of molecule per unit volume is very small. This is only possible at high temperature and low pressure.
Q: The observer hears a sound from the source which is moving away from the observer who is stationary. Determine the frequency of the sound
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63c8f650be373f6c954abbda- 1It is halvedtrue
- 2It remains the samefalse
- 3It reaches infinityfalse
- 4It gets doubledfalse
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Answer : 1. "It is halved"
Explanation :
If the observer is moving away from the source ((Figure)), the observed frequency can be found: λs=vTo−voTovTs=(v−vo)Tov(1fs)=(v−vo)(1fo)fo=fs(v−vov).