Q9. In a system of units if force (F), acceleration (A) and time (T) are taken as fundamentals units then the dimensional formula of energy is FA2TFAT2FA2TFAT Answer: FAT2

Q. Which of the following is a dimensional constant? Gravitational constantDielectric constantRefractive indexRelative density Answer: Gravitational constant

Q. Which of the following physical quantities has different dimensions? EnergyWatt hourMomentumWork Answer: Momentum

Q. Two physical quantities whose dimensions are not same, cannot be multiplied with each otherdividedadded or substracted in the same expressionadded together Answer: added or substracted in the same expression

Q. The most suitable instrument for measuring the size of an atom is. Electron microscopeVernier calliperOptical MicroscopeScrew gauge Answer: Electron microscope

Q. Torr’ is the unit of pressurevolumedensityflux Answer: pressure

Q.14. The numbers 5.355 and 5.345 on rounding off to 3 significant figures will give 5.35 and5.345.36 and5.355.35 and5.355.36 and5.34 Answer: 5.36 and5.34

Q. The respective number of significant figures for the numbers 23.023, 0.0003 and 2.1×10-3 are 5, 1, 25, 1, 55, 5, 24, 4, 2 Answer: 5, 1, 2

Q. Which two of the following five physical parameters have the same dimensions? I. Energy density II. Refractive index III. Dielectric constant IV. Young’s modulus V. Magnetic field I and IVIII and VI and III and V Answer: I and IV

Q. The length, breadth and height of a rectangular block of wood were measured to be l = 12.13 ± 0.02 cm, b = 8.16 ± 0.01cm and h = 3.46 ± 0.01cm. 0.88%0.58%0.78%0.68% Answer: 0.58%