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 1151: Electrical appliances at home are normally earthed so that
Options:
A) the appliances are maintained at a lower p.d than the earth
B) both the a.c and d.c sources can be used
C) a person touching the appliances is safe from electric shock
D) the appliances are maintained at a higher p.d than the earth
Show Answer
The correct answer is C .
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Question 1152:

In the diagram above, a ray of light passes from glass into air, if the angle of incidence in glass is and angle of refraction in air is which of following statements is true???
Options:
A)
B) the efractive index of glass is
C) The ray suffers total internal reflection if is greater than the critical angle
D) the refractive index of glass is
Show Answer
The correct answer is D .
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Question 1153:
A 40 kW electric cable is used to transmit electricity through a resistor of resistance 2.0Ω at 800 V. The power loss as internal energy is?
Options:
A) 4.0 x 102W
B) 5.0 x 102W
C) 4.0 x 103W
D) 5.0 x 103W
Show Answer
The correct answer is D .
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Question 1154: The maximum power transfer occur in a cell when the external resistance is
Options:
A) Twice the internal resistance of the cell
B) The same as the internal resistance of the cell
C) Greater than the internal resistance of the cell
D) Less than the internal resistance of the cell
Show Answer
The correct answer is B .
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Question 1155:

A force of 5N act at a point Y on a rod XYZ as shown in the diagram above, if XY is 2m. What is the moment of the force about point X?
Options:
A) 0Nm
B) 3Nm
C) 7Nm
D) 10Nm
Show Answer
The correct answer is A .
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Question 1156: The absolute refractive indices of glass and water are and respectively. The refractive index at the interface when a ray travels from water to glass is
Options:
A)
B)
C)
D)
E) 2
Show Answer
The correct answer is C .
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Question 1157: A generator manufacturing company was contracted to produce an a.c dynamo but inadvertently produced a d.c dynamo. To correct this error, the
Options:
A) armature coil should be made of silver
B) commutator should be replaced with slip ring
C) commutator should be replaced with split rings
D) armature coil should be made of aluminium
Show Answer
The correct answer is B .
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Question 1158:
If a force of 50N stretches a wire from 20m to 20.01m, what is the amount of force required to stretch the same material from 20m to 20.05m?
Options:
A) 250N
B) 200N
C) 100N
D) 50N
Show Answer
The correct answer is A .
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Question 1159: The photocell works on the principle of the
Options:
A) voltaic cell
B) emision of electrons by incident radiation
C) emision of protons by incident electrons
D) photographic plate
Show Answer
The correct answer is B .
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Question 1160:

The diagram above show s the force-extension curve of a piece of wire. The energy stored when the wire is stretched from E to F is
Options:
A) 7.5 x 10-3J
B) 2.5 x 10-3J
C) 1.5 x 10-2J
D) 7.5 x 10-1J
Show Answer
The correct answer is A .