CBSE
Multiple Choice QuestionsA force F is given by F =at + bt2 ,where, t is time. What are the dimensions of a and b ?
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 of circular scale division coincides with 25 divisions above the reference level. If screw gauge has a zero error of –0.004 cm, the correct diameter of the ball is
0.521 cm
0.525 cm
0.529 cm
0.053
Dimensions of resistance in an electrical circuit, in terms of the dimension of mass M, of length L, of time T and of current I, would be:
[ML2T-3I-1]
[ML2T-2]
[ML2T-1I-1]
[ML2T-1I-1]
Which two of the following five physical parameters have the same dimensions?
1) Energy density
2) refractive index
3) dielectric constant
4) Young's modulus
5) Magnetic field
2 and 4
3 and 5
1 and 4
1 and 4
The physical quantity having the dimensions [ M-1 L-3 T3 A2 ] is
resistance
resistivity
electrical conductivity
electromotive force
The length, breadth and thickness of a block are given by l = 12 cm, b = 6 cm and t = 2.45 cm. The volume of the block according to the idea of significant figures should be
1 × 102 cm3
2 × 102 cm3
1.76 × 102 cm3
None of these
The physical quantity of the dimensions of length that can be formed out of c, G and e/4πε0 is [c is the velocity of light, G is the universal constant of gravitation and e is charge]
In a system of units if force (F), acceleration (A), and time (T) are taken as fundamental units, then the dimensional formula of energy is:
FA2T
FAT2
F2AT
FAT
Dimensions of resistance in an electrical circuit, in terms of dimension of mass M, of length L, of time T and of current I, would be
[ M L2 T-3 I-1]
[M L2 T-1]
[M L2 T-1 I-1]
[M L2 T-3 I-2 ]
The velocity v of a particle at time t is given by 
where a, b and c are constants, The dimensions of a, b and c are respectively:
