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 1661: Four lenses are being considered for use as a microscope objective. Which of the following focal lengths is most suitable?
Options:
A) -5mm
B) +5mm
C) -5cm
D) +5cm
Show Answer
The correct answer is B .
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Question 1662: The velocities of light in air and glass are 3.0 x 108ms-1 and 2.0 x 108ms-1 respectively. If the angle of refraction is 30°, the sine of the angle of incidence is
Options:
A) 0.33
B) 0.50
C) 0.67
D) 0.75
Show Answer
The correct answer is D .
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Question 1663: An electric device is rated 2000W, 250V. Calculate the maximum current it can take
Options:
A) 9A
B) 8A
C) 7A
D) 6A
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The correct answer is B .
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Question 1664: What is the effect of the increase in the size of the hole of a pin-hole camera on the image? it
Options:
A) gives a blurred image
B) corrects for chromatic aberration
C) magnifies the image
D) brings the image into a sharper focus
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The correct answer is A .
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Question 1665: Which of the following elements are real magnetic materials?
Options:
A) Iron, steel and nickel
B) copper, steel and iron
C) lead, iron and brass
D) glass, lead and steel
E) stone, air and iron
Show Answer
The correct answer is A .
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Question 1666:

When the sun, moon and the earth are as shown in the diagram above an observer standing in X is in
Options:
A) Penumbra and sees a partial eclipse
B) Penumbra and sees a total eclipse
C) umbra and sees a partial eclipse
D) umbra and sees a total eclipse
Show Answer
The correct answer is A .
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Question 1667: How many grams of water at 17oC must be added to 42g of ice at 0oC to melt the ice completely? [specific latent heat of fusion of ice = 3.4 x 105Jkg-1, specific heat capacity of water = 4200Jkg-1k-1]
Options:
A) 200g
B) 300g
C) 320g
D) 400g
Show Answer
The correct answer is A .
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Question 1668:
A few grains of table salt were put in a cup of cold water, kept at constant temperature and left undistributed. Eventually all the water tested salty. This action isdue to?
Options:
A) convection
B) osmosis
C) capillarity
D) diffusion
Show Answer
The correct answer is D .
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Question 1669: When an alternating current given by I = 10sin (120π)t passes through a 12Ω resistor, the power dissipated in the resistor is
Options:
A) 1200W
B) 600W
C) 120W
D) 30W
Show Answer
The correct answer is A .
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Question 1670: In photoelectric effect, electrons will leave the metal surface when illuminated by light of appropriate frequency if the photon energy is
Options:
A) greater than the work function
B) less than the work function
C) equal to the work function
D) equal to the maximium kinetic energy of the electron
Show Answer
The correct answer is A .