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.
The product of force and time is?
Impulse
Momentum
Inertia
Friction
Correct answer is A
An impulse is equal to the net force on the object times the time period over which this force is applied. Impulse is derive from the equation F = ma, which comes from Newton's second law of motion