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.
-
Question 121:

The diagram above shows forces 4N, 6N, 10N and 8N which act at a point O in the directions indicated. the net horizontal force is
Options:
A) 13N
B) 17N
C) √3N
D) 7√3N
Show Answer
The correct answer is A .
-
Question 122: A dynamo primarily combines
Options:
A) mechanical energy into electrical energy
B) electrical energy into kinetic energy
C) potential energy into kinetic energy
D) kinetic energy into potential energy
Show Answer
The correct answer is A .
-
Question 123: A bullet fired at a wooden block of thickness 0.15m manages to penetrate the block. If the mass of the bullet is 0.025kg and the average resisting force of the wood is 7.5 x 103N, calculate the speed of the bullet just before it hits the wooden block.
Options:
A) 450ms-1
B) 400ms-1
C) 300ms-1
D) 250ms-1
Show Answer
The correct answer is C .
-
Question 124: The device in which one circuit controls another, especially if the current in the second circuit is large or dangerous is known as
Options:
A) Electromagnetic devices
B) Magnetic relay device
C) None at all
D) Sextant
Show Answer
The correct answer is B .
-
Question 125: A block and tackle pulley arrangement has 6 pulleys in which an effort of 50N supports a load of 200N, calculate the efficiency of the machine
Options:
A) 80.0%
B) 76.6%
C) 66.7%
D) 60.7%
Show Answer
The correct answer is C .
-
Question 126:
A car moving with a speed of 90kmh-1 was brought uniformly to rest by the application of the brakes in 10s. How far did the car travel after the brakes were applied?
Options:
A) 125m
B) 150m
C) 250m
D) 15km
Show Answer
The correct answer is A .
-
Question 127:
Calculate the absolute pressure at the bottom of a lake at a depth of 32.8 m. Assume the density of the water is 1 x 10^3 kgm-3 and the air above is at a pressure of 101.3 kPa.
[Take g = 9.8 ms-2]
Options:
A) 422.7
B) 220.14
C) 464.53
D) 321.74
Show Answer
The correct answer is A .
-
Question 128: If a sonometer has a fundamental frequency of 450HZ, what is the frequency of the fifth overtone?
Options:
A) 2700Hz
B) 456Hz
C) 444Hz
D) 75Hz
Show Answer
The correct answer is A .
-
Question 129: An object of weight 80kg on earth is taken to a planet where acceleration due to gravity is one-third of its value on earth. The weight of the object on the planet is
Options:
A) 48N
B) 12N
C) 27N
D) 36N
Show Answer
The correct answer is C .
-
Question 130:
The pitch of an acoustic device can be increased by
Options:
A) decreasing the loudness
B) increasing the intensity
C) increasing the frequency
D) decreasing the intensity
Show Answer
The correct answer is C .