A student performs an experiment to determine the Young's modulus of a wire exactly 2cm long, by Searle's method. In a particular reading, the student measures the extension in the length of the wire to be 0.8 mm with an uncertainty of ± 0.05 mm at a load of exactly 1.0 kg. The student also measures the diameter of the wire to be 0.4 mm with an uncertainty of ±0.01 mm. Take g = 9.8 m/s2 (exact). The Young's modulus obtained from the reading is -
A calorie is a unit of heat and equals 4.2 J. Suppose we employ a system of units in which of the unit of mass is α kg, the unit of length is β metre and the unit of time is second. In this new system, 1 calorie =
r.m.s velocity of nitrogen molecules at NTP is-
The correct order in which the dimensions of
length increases in the following quantities is
(i) Volume,
(ii) Stress
(iii) Impulse
(iv) Planck's constant
If 1 g cm s–1 = x newton-second, then the number x is equal to -
The velocity of a freely falling body changes as gphq where g is acceleration due to gravity and h is the height. The values of p and q are
Consider a new system of units in which c (speed of light in vaccum), h (Planck's constant) and G (gravitational constant) are taken as fundamental units. Which of the following would represent mass in this new system ?
A wave is represented by y = a sin (At – Bx + C) where A, B, C are constants. The Dimensions of A, B, C are (here y and x are displacement and distance and t is time) -
Dimensional formula for the Planck's constant is -
Which of the following is unitless quantity ?
The dependency of speed of water surface waves (capillary waves) on the density of water (ρ) their wavelength (λ) and surface tension (γ) is -
The resistive force on a very-high-velocity object of area A passing through a gas of density ρ at a velocity v is
Force ~ Ar ρs vt
Then –
If force, length and time were the fundamental units, then the dimensional formula of mass would have been -
To keep on object moving in a circle at constant speed requires a force F α mavbrc. According to dimensional analysis the a, b, c are -
A highly rigid cubical block A of small mass M and side L is fixed rigidly on the another cubical block of same dimensions and of low modulus of rigidity η such that the lower face of A completely covers the upper face of B. The lower face of B is rigidly held on the horizontal surface. A small force F is applied perpendicular to one of the side faces of A. After the force is withdrawn, block A excutes small oscillations, the time period of which is given by –
If a and b are two physical quantities having different dimensions then which of the following can denote a new physical quantity
The velocity 'v' (in cm/s) of a particle is given in terms of time 't' (in s) by the equation
v = at +
The dimensions of a, b and c are
Force F is given in terms of time t and distance x by
F = A sin C t + B cos D x
Then the dimensions of and
are given by
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