Physics Questions and Answers
If you want to learn more about the nature and properties of matter and energy or you're simply preparing for a Physics exam, these Physics past questions and answers are ideal for you.
If you want to learn more about the nature and properties of matter and energy or you're simply preparing for a Physics exam, these Physics past questions and answers are ideal for you.
A 40W instrument has a resistance 90 Ohms. On what voltage should it be operated normally
60V
150V
225V
360V
Correct answer is A
P = 40W
R = 90W
V = ?
P = \(\frac{V^2}{R}\)
V\(^2\) = PR = 40 x 90
V\(^2\) = 3000
V = √3600
V = 60N
Which of the following is an essential physical property of the wires uses for making fuses ?
Low density
Hypothermal conductivity
Low electrical resistivity
Low melting point
Correct answer is D
Fuse wires have a low melting point so that if a huge amount of current is passed through it to any appliance than that wire would melt and stop the appliance from getting damaged by not letting the current pass any further.
330.0m
335.4m
660.0m
670.8m
Correct answer is B
Recall V = F × \(\lambda\)
= 260 × 1.29
= 335.4ms\(^{-1}\)
Echo time = \(\frac{2}{2}\) = 1 sec
Distance = v x t = 335.4 x 1
= 335.4m
0.33
0.50
0.67
0.90
Correct answer is D
= \(\frac{2}{3}\)(0.5)\(^3\)
Mass of liquid displaced = mass of floating cube = 75kg
Density of liquid = \(\frac{mass}{volume}\)
= \(\frac{75}{(\frac{7}{3(0.5)})}\) × 3
= 0.9 × 103kgm\(^{-3}\)
R.D of liquid = \(\frac{(0.9 )}{(1.0)}\) × 103
= 0.9
Which of the following concepts is not an evidence of the particles nature of matter?
Diffusion
Brownian motion
Diffraction
Esterification
Correct answer is D
Diffusion is the net movement of molecules/atoms from a region of high concentration to low concentration.
Brownian motion is the erratic random movement of microscopic particles in a field.
Diffraction is the various phenomena that occur when a wave encounters an obstacle.