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Earn 100

A sextant is used to measure

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Important Questions on Physical World and Measurement

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Match the physical quantities with their correct SI units.

  List-I   List-II
(A) Planck's constant (I) kg m s-2
(B) Torque (II) kg-1 m3
(C) Weight (III) m2 kg s-1
(D) Specific volume (IV) kg m2 s-2

The correct match is

MEDIUM
The angular diameter of a planet measured from earth is 90". If the diameter of the planet is π×106 m, then its distance from the earth is
MEDIUM
Consider a particle moving along the positive direction of X-axis. The velocity of the particle is given by v=αx (α is a positive constant). At time t=0, if the particle is located at x=0, the time dependence of the velocity and the acceleration of the particle are respectively.
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If E and H represents the intensity of electric field and magnetizing field respectively, then the unit of EH will be:

HARD
A person in front of a mountain is beating a drum at the rate of 40 per minute and hears no distinct echo. If the person moves 90 m closer to the mountain, he has to beat the drum at 60 per minute to not hear any distinct echo. The speed of sound is
 
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The angle of 1' (minute of arc) in radian is nearly equal to
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A student measured the diameter of a small steel ball using a screw gauge of least count 0.001 cm. The main scale reading is 5 mm and zero division of the circular scale coincides with 25 divisions above the reference level. If the screw gauge has a zero error of -0.004 cm. the correct diameter of the ball is__________
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The nearest star to our solar system is 4.3 light years away. The distance of this star in Parsec is (Mean distance between the earth and the sun =1.5×1011 m and one light year =9.46×1015 m
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A spherometer has 20 threads per cm. Its circular scale has 100 divisions. The least count of the sphere is
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A huge circular arc of length 4.4 ly subtends an angle 4s at the centre of the circle. How long it would take for a body to complete 4 revolution if its speed is 8 AU per second?
Given : 1 ly=9.46×1015 m

1 AU=1.5×1011 m

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The angular speed of a fly-wheel making 180 rpm is ________
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Match the following?

Column -I Column -II
(a) Conductance (i) Gray
(b) Magnetic Induction (ii) Lumen
(c) Absorbed dose (iii) Tesla
(d) Luminous flux (iv) Siemens

 

MEDIUM
Velocity v and acceleration a in two systems of units 1 and 2 are related as v2=nm2v1 and a2=a1mn respectively. Here m and n are constants. The relations for distance and time in two systems respectively are
EASY
The distance of the Sun from earth is 1.5×1011 m and its angular diameter is 2000'' when observed from the earth. The diameter of the Sun will be
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The period of oscillation of a simple pendulum is T=2πlg.  Measured value of l is 20.0 cm, known to 1 mm  accuracy and time for 100 oscillations of the pendulum is found to be 90 s using a wristwatch of 1 s resolution. The accuracy in the determination of g is 
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A plano-convex lens of unknown material and unknown focal length is given. With the help of a spherometer we can measure the