Physics is the science that studies the nature and properties of matter and energy. It covers topics like motion, heat, light, sound, electricity, magnetism, and the structure of atoms.
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Question 161:
I. The frictional force is independent of the area of the surfaces in conduct
II. The frictional force depends on the nature of the surfaces in contact
III. The frictional force depends on the speed of sliding
IV. The frictional force is directly proportional to the normal reaction.Which combination of the above is true of sliding friction?
Options:
A) I, III and IV
B) I, II and IV
C) I, II and III
D) II, III and IV
Show Answer
The correct answer is B .
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Question 162: The blade of a hoe feel colder to touch in the morning than the wooden handle because the
Options:
A) handle is a better conductor of heat than blade
B) handle contains stored energy in form of heat
C) blade is a better conductor of heat than the handle
D) blade is placed at a lower temperature than the heat
Show Answer
The correct answer is C .
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Question 163:

The electric field between two - point charges is shown in the diagram above. What types of charges are at X and Y?
Options:
A) Both X and Y are negative
B) Both X and Y are positive
C) X is positive and Y is negative
D) X is negative and Y is positive
Show Answer
The correct answer is B .
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Question 164: A vibrator of frequency 60Hz is used in generating transverse stationary waves in a long thin wire, If the average distance between successive nodes on the wire is 45cm, find the speed of the transverse waves in the wire.
Options:
A) 27ms-1
B) 54ms-1
C) 90ms-1
D) 108ms-1
Show Answer
The correct answer is A .
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Question 165: A liquid-in-glass thermometer should quickly register temperature changes. This is achieved by choosing a liquid that
Options:
A) is opaque
B) has high density
C) has regular expansion
D) has a high thermal conductivity
E) can wet glass
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The correct answer is D .
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Question 166: A current of 0.5A flows through a resistor when connected to a 40-V battery. How much energy is dissipated in 2 minutes?
Options:
A) 1200J
B) 1500J
C) 2400J
D) 96000J
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The correct answer is C .
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Question 167: Calculate the work done in charging a capacitor of capacitance 20µF through a potential difference of 1000V.
Options:
A) 0.02 J
B) 0.10 J
C) 0.20 J
D) 1.00 J
E) 10.00 J
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The correct answer is E .
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Question 168: When a ship sails from salt water into fresh water, the fraction of its volume above the water surface will
Options:
A) increase
B) decrease
C) remain the same
D) increase then decrease
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The correct answer is B .
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Question 169: A pencil is placed vertically between a concave mirror and its focal point. The image of the pencil in the mirror will be
Options:
A) real, inverted and diminished
B) virtual, inverted and enlarged
C) real, erect and enlarged
D) virtual, erect and enlarged
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The correct answer is D .
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Question 170:
A resistance R is connected across the terminal of an electric cell of internal resistance 2Ω and the voltage was reduced to 3/5 of its nominal value.
The value of R is
Options:
A) 3 Ω
B) 2 Ω
C) 1 Ω
D) 6 Ω
Show Answer
The correct answer is A .