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 171: The core of an efficient transformer should consist of laminated pieces of metal in order to
Options:
A) increase the heat produced by increasing the eddy current
B) increase the heat produced by reducing the eddy current
C) reduce the heat produced by increasing the eddy current
D) reduce the heat produced by reducing the eddy current
Show Answer
The correct answer is D .
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Question 172:
Heat may be transferred by conduction, convention and radiation. By which of these methods does heat travel through vacuum?
Options:
A) Conduction only
B) Convection only
C) Radiation only
D) All these methods
Show Answer
The correct answer is C .
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Question 173: A piano wire 0.5m long has a total mass of 0.01kg and is stretched with a tension of 800N. Calculate the frequency of the wire when it sounds its fundamental note
Options:
A) 200Hz
B) 100Hz
C) 4Hz
D) 2Hz
Show Answer
The correct answer is A .
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Question 174:

What is the resultant resistance in the circuit given above?
Options:
A) 11Ω
B) 8Ω
C) 4Ω
D) 3.6Ω
E) 4.3Ω
Show Answer
The correct answer is B .
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Question 175: A travelling wave moving from left to right has an amplitude of 0.15m, a frequency of 550Hz and a wavelength of 0.01m. The equation describing the wave is
Options:
A) y = 0.15 sin 200π(x - 5.5t)
B) y = 0.15 sin π(0.01x - 5.5t)
C) y = 0.15 sin 5.5π(x - 200t)
D) y = 0.15 sin π(550x - 0.01t)
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The correct answer is A .
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Question 176: A parallel plate capacitor has a common plate area of 5 x 10-8m2 and plate separation of 2 x 103m, Assuming free space, What is the capacitance? [o = 9.0 X 10-12C2N-1m-2]
Options:
A) 2.25 x 10-17F
B) 4.50 x 10-17F
C) 2.25 x 10-16F
D) 4.50 x 10-16F
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The correct answer is C .
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Question 177: If the refractive index of a medium is V2, what is the critical angle?
Options:
A) 45o
B) 50o12'
C) 56o25'
D) 75o
E) 90o
Show Answer
The correct answer is A .
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Question 178:

The diagram above shows a lift pump with valves at P and Q. During a downward stroke of the piston
Options:
A) both valves are open
B) P is open while Q is closed
C) P is closed while Q is open
D) Both valves are closed
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The correct answer is B .
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Question 179: The voltage of the domestic electric supply is represented by the equation V = 311 sin314.2t. Determine the frequency of the a.c. supply [ = 3.142]
Options:
A) 50.0Hz
B) 100.0Hz
C) 311.0Hz
D) 314.2Hz
Show Answer
The correct answer is A .
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Question 180: Which of the following correctly explains why soft iron is proffered to steel in electromagnets? i. soft iron is more readily magnetized than steel. ii. soft iron is more readily demagnetized than steel. iii. soft iron retains magnetism more than steel.
Options:
A) i only
B) ii and iii only
C) i and ii only
D) i, ii, and iii.
Show Answer
The correct answer is C .