For A refrigerator transferring heat from its cold interior, identify the physical principle illustrated.
Correct answer: D
External work allows heat to move from colder to warmer surroundings.
0 correct out of 0 attempted (0%)
Correct answer: D
External work allows heat to move from colder to warmer surroundings.
Correct answer: A
I is correct: A transformer changing alternating voltage → Electromagnetic induction. Changing magnetic flux induces an emf in another coil. II is correct: An ambulance siren changing pitch as it passes → Doppler effect. Relative motion changes the frequency heard by the observer.
Correct answer: D
I is correct: A hydraulic lift multiplying force → Pascal's law. Pressure applied to confined fluid is transmitted throughout it. II is incorrect: A black surface warming strongly in sunlight → Greater absorption of radiation. Dark matte surfaces are generally effective absorbers.
Correct answer: A
Displaced water can provide an upthrust equal to the ship's weight.
Correct answer: D
I is incorrect: An optical fibre guiding light → Total internal reflection. Light can be confined within a higher-index core. II is incorrect: A rocket accelerating by ejecting gas → Conservation of momentum. Gas and rocket gain oppositely directed momentum.
Correct answer: A
I is correct: A transformer changing alternating voltage → Electromagnetic induction. Changing magnetic flux induces an emf in another coil. II is incorrect: A fuse melting under excess current → Heating effect of current. Joule heating raises the fuse element's temperature.
Correct answer: B
A temperature gradient changes air's refractive index.
Correct answer: C
I is correct: A spoon appearing bent in water → Refraction. Light changes direction between media of different optical density. II is incorrect: An ambulance siren changing pitch as it passes → Doppler effect. Relative motion changes the frequency heard by the observer.
Correct answer: B
I is correct: A passenger lurching forward when a bus stops → Inertia. The body tends to retain its previous state of motion. II is correct: A hydraulic lift multiplying force → Pascal's law. Pressure applied to confined fluid is transmitted throughout it.
Correct answer: D
Light can be confined within a higher-index core.
Correct answer: B
I is correct: A refrigerator transferring heat from its cold interior → Work-driven heat transfer. External work allows heat to move from colder to warmer surroundings. II is correct: A ship floating despite being made of steel → Buoyancy. Displaced water can provide an upthrust equal to the ship's weight.
Correct answer: A
Gas and rocket gain oppositely directed momentum.
Correct answer: D
I is correct: A transformer changing alternating voltage → Electromagnetic induction. Changing magnetic flux induces an emf in another coil. II is incorrect: A black surface warming strongly in sunlight → Greater absorption of radiation. Dark matte surfaces are generally effective absorbers.
Correct answer: B
Pressure applied to confined fluid is transmitted throughout it.
Correct answer: A
I is incorrect: An optical fibre guiding light → Total internal reflection. Light can be confined within a higher-index core. II is correct: A fuse melting under excess current → Heating effect of current. Joule heating raises the fuse element's temperature.
Correct answer: B
I is incorrect: A sound becoming higher pitched → Increase in frequency. Pitch depends mainly on vibration frequency. II is incorrect: Water cooling an earthen pot → Evaporative cooling. Escaping water molecules carry away energy.
Correct answer: B
Changing magnetic flux induces an emf in another coil.
Correct answer: D
I is correct: A ship floating despite being made of steel → Buoyancy. Displaced water can provide an upthrust equal to the ship's weight. II is correct: An optical fibre guiding light → Total internal reflection. Light can be confined within a higher-index core.
Correct answer: B
I is incorrect: A hydraulic lift multiplying force → Pascal's law. Pressure applied to confined fluid is transmitted throughout it. II is correct: A spoon appearing bent in water → Refraction. Light changes direction between media of different optical density.
Correct answer: C
Pitch depends mainly on vibration frequency.
Correct answer: A
I is correct: Water cooling an earthen pot → Evaporative cooling. Escaping water molecules carry away energy. II is incorrect: An ambulance siren changing pitch as it passes → Doppler effect. Relative motion changes the frequency heard by the observer.
Correct answer: B
I is incorrect: An optical fibre guiding light → Total internal reflection. Light can be confined within a higher-index core. II is incorrect: A sound becoming higher pitched → Increase in frequency. Pitch depends mainly on vibration frequency.
Correct answer: A
Escaping water molecules carry away energy.
Correct answer: C
I is incorrect: A ship floating despite being made of steel → Buoyancy. Displaced water can provide an upthrust equal to the ship's weight. II is correct: Water cooling an earthen pot → Evaporative cooling. Escaping water molecules carry away energy.
Correct answer: B
I is correct: Water cooling an earthen pot → Evaporative cooling. Escaping water molecules carry away energy. II is correct: A hydraulic lift multiplying force → Pascal's law. Pressure applied to confined fluid is transmitted throughout it.