Frequently Asked Questions
The inertia of an object tends to cause the object
A: to increase its speed
B: to decrease its speed
C: to resist any change in its state of motion
D: to decelerate due to friction
The inertia is the physical property of a body of an object tends to cause the object to resist any change in its state of rest or motion. The inertia is directly dependent on the mass of the body. The object will stay at rest if it is at rest or will stay in motion if the object is already in motion.
Option C is correct
Two waves are represented by the equations y1
y1 = asin ( ωt + kx + 0.57 )m and y2 = acos ( ωt + kx )m, where x is in metre and t in second. The phase difference between them is
A: 0.57 radian
B: 1.0 radian
C: 1.25 radian
D: 1.57 radian
The twwo waves can be written as
So the phase difference is
The correct option is (B).
A Carnot engine has an efficiency of 1/6
When the temperature of the sink is reduced by 62ºC , its efficiency is doubled. The temperatures of the source and the sink are, respectively
A: 124ºC ,62ºC
B: 37ºC ,99ºC
D: 99ºC ,37ºC
The efficiency of the carnot’s engine can be given by
We can also write
The correct option is (D).⇒ ( Tsource=372K=99ºC
Now Tsink=5/6×372K=310K=37ºC )
The value of acceleration due to gravity
A: is same on equator and poles
B: is least on poles
C: is least on equator
D: increases from pole to equator
The acceleration can be given by the formula
g=G M/R2 where g= acceleration,G is the gravitional constant. M is the mass of the earth.R is the distance of the surface and the centre of earth.
The acceleration is less at the equator because the distance between the surface of the earth and the centre is more than the pole .
The value of the acceleration due to gravity is least on equator.
So option (C ) is correct.