Physical World and Measurement

How many numbers of base SI units are there?

• 5

• 7

• 9

• 10

Identify the physical parameters that are having the same dimensions from the below-given list:

(i) Magnetic field

(ii) Energy density

(iii) Refractive index

(iv) Young’s modulus

(v) Dielectric constant

• (ii) and (iv)

• (i) and (v)

• (iii) and (iv)

• (iv) and (iii)

Calculate the value of the dot product of the two vectors whose magnitudes are 3 units and 4 units and their resultant is 1 unit.

• 0

• -1 unit

• +6 units

• -12 units

What is the percentage error in the measurement of the kinetic energy of a body, if there is a positive error of 50% in the speed of the body

• 125%

• 100%

• 30%

• 50%

Which the following is a dimensionless quantity

• Refractive index

• Velocity

• Planck’s constant

• Gravitational constant

Following are the readings obtained while measuring the diameter of a wire by using the screw gauge0 mm is the main scale reading

52 divisions are the circular scale reading

What is the diameter of the wire if 1 mm on the main scale is equal to the 100 divisions on the circular scale

• 0.016 cm

• 0.052 cm

• 0.15 cm

• 0.05 cm

What is the dimensional formula of torque and energy

• $[ML^{-3}T^{-2}]and[MLT^{-2}]$

• $[ML^2T^{-2}]and[MLT^{-2}]$

• $[ML^2T^{-2}]and[ML^2T^2]$

• $[MLT^2]and[ML^2T^2]$

Find the relative error of y, if y=x²

• $\frac{△x}{x}$

• $\frac{2△x}{x}$

• $\frac{\left(△x\right)^2}{x}$

• $\left(△x\right)^2$

From the given three fundamental constants, select the combination that gives the dimension of length

(i) Newton’s gravitational constant (G)

(ii) Speed of light in a vacuum (c)

(iii) Planck’s constant (h)

• $\sqrt{\frac{hc}{G}}$

• $\sqrt{\frac{Gc}{h^{\frac{3}{2}}}}$

• $\sqrt{\frac{hG}{C^{\frac{5}{2}}}}$

• $\sqrt{\frac{hG}{c^{\frac{3}{2}}}}$

The word Science originates from the Latin verb Scientia meaning

• to experience

• to know

• to see

• to observe