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The error in two readings of A are 0.01 and 0.03, then mean absolute error is ?
Answer : d
Solution : Absolute mean error = (a1a2)/2
[0.01(0.03)]/2
= 0.04/2
= 0.02.
A boy is running over a circular track with uniform speed of 10 m/s. Find the average velocity for movement of boy from A to B. (in m/s)
A uniform flexible chain of mass m and length 2 l hangs in equilibrium over a smooth horizontal pin of negligible diameter. One end of the chain is given a small vertical displacement so that the chain slips over the pin.The speed of chain when it leaves pin is
A uniform circular disc of radius a is taken. A circular portion of radius b has been removed from it as shown in figure. If the centre of hole is at a distance c from the centre of the disc, the distance x_{2} of the centre of mass of the remaining part from the intial centre of mass O is given by
The radius of gyration of a uniform rod of length L about on axis passing through its centre of mass is
Three thin rods each of length L and mass M are placed along x,y and z axis such that one end of each rod is at origin. The moment of inertia of this system about zaxis is
A point P (R √3,0,0) lies on the axis of a ring of mass M and radius R. The ring is located in yz plane with its centre at origin O. A small particle of mass m starts from P and reaches O under gravitational attraction only. Its speed of O will be
A particle undergoing SHM has the equation : x = A sin (ω + φ ), where x represents the displacement of the particle. The kinetic energy oscillates with time period
The phase difference between the two simple harmonic oscillations
y_{2} = sin (ωt) + cos (ωt)
Pressure versus temperature graph of an ideal gas of equal number of moles of different volumes are plotted as shown in figure. Choose the correct alternative
A system undergoes a cyclic process in which it absorbs Q_{1} heat and gives out Q_{2} heat. The efficiency of the process is η and work done is W. Select the correct statement
A cylinder of radius R, made of a material of thermal conductivity k_{1}, is surrounded by a cylindrical shell of inner radius R and outer radius 2R. The shell is made of a material of thermal conductivity k2. The two ends of the combined system are maintained at two different temperatures. There is no loss of heat across the cylindrical surface and the system is in steady state. The effective thermal conductivity of the system is
A small source of sound moves on a circle as shown in figure and an observer in standing on O. Let n_{1}, n_{2} and n_{3} be the frequencies heard when the source is at A,B and C respectively. Then
Direction : Read the following question and choose
A. If both Assertion and Reason are correct and reason is the correct explanation of assertion
B. If both Assertion and Reason are true, but Reason is not correct explanation of the Assertion
C. If Assertion is true, but the Reason is false
D. If Assertion is false, but the Reason is true
E. If both assertion and reason are false
Assertion : A room can be cooled by opening the door of a refrigator in a closed room
Reason : Heat flows from lower temperature (refrigerator) to higher temperature (room)
1 videos25 docs146 tests

1 videos25 docs146 tests
