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 1421: To produce a parallel beam of light from a concave mirror, the distance at a which the lamp should be placed from the mirror is equal to
Options:
A) the focal length
B) two times the focal length
C) the distance of the image
D) two times the radius of curvature
Show Answer
The correct answer is A .
-
Question 1422:
I. It retains its magnetic much longer than steel.
II. It is more easily magnetized than steel.
III. It is more easily demagnetized than steel.
IV. It produces a stronger magnet than steel.
Which combination of the above makes iron preferable to steel in the making of electromagnets?
Options:
A) I and II only
B) II and III only
C) I, III, and IV only
D) II, III and IV only
Show Answer
The correct answer is B .
-
Question 1423: Two masses 40g and 60g respectively, are attached firmly to the ends of the light meter rule. The center of gravity of the system is
Options:
A) at the mid-point of the meter rule
B) 40cm from the lighter mass
C) 40cm from the heavier mass
D) 60cm from the heavier mass
E) indeterninate because the meter-rule is light
Show Answer
The correct answer is C .
-
Question 1424:

From the diagram above, the inductive reactance and the resistance R are respectively
Options:
A) 50Ω and 45Ω
B) 25Ω and 51Ω
C) 20Ω and 50Ω
D) 10Ω and 49Ω
Show Answer
The correct answer is D .
-
Question 1425:
From the diagram above, if the potential difference across the resistor, capacitor and inductor are 60V, 120V and 30V respectively, the effective potential difference is
Options:
A) 81
B) 67
C) 59
D) 73
Show Answer
The correct answer is B .
-
Question 1426: Radio waves have a velocity of 3 x 108ms-1. A radio station sends out a broadcast on a frequency of 800kHz. The wavelength of the broadcast is
Options:
A) 375.0m
B) 267.0m
C) 240.0m
D) 37.5m
E) 26.7m
Show Answer
The correct answer is A .
-
Question 1427:
Which of the following is not a vector quantity?
Options:
A) momentum
B) force
C) temperature
D) displacement
Show Answer
The correct answer is C .
-
Question 1428:
A cannon is fired from town X, after how long is the sound heard at a town Y 4.95 km away?
[velocity of sound in the air = 330 ms-1]
Options:
A) 30 s
B) 10 s
C) 10 s
D) 15 s
Show Answer
The correct answer is D .
-
Question 1429: the ray which causes gas molecules to glow is known as
Options:
A) cathode ray
B) anode ray
C) molecular ray
D) gamma ray
Show Answer
The correct answer is A .
-
Question 1430: The relationship between L and the wavelength I of the stationary wave is
Options:
A) 2L =
B) L =
C) L =
D) 4L = 3
Show Answer
The correct answer is D .