lf a calculated value 2.7456 g contains only three significant figures, the two insignificant digits in it are 

(1) 2 and 7

(2)  7 and 4

(3) 6 and 5

(4)  4 and 6

An object of mass 4.237 g occupies a volume 1.72 cm${}^3$. The density of the object to appropriate significant figures is 

(1) 2.46 g cm${}^{-3}$

(2) 2.463 g cm${}^{-3}$

(3) 2.5 g cm${}^{-3}$

(4) 2.50 g cm${}^{-3}$

Round off the value 2.845 to three significant figures. 

(1) 2.85 

(2) 2.84

(3) 2.80

(4) 2.86

A length 5.997 m rounded off to three significant figures is written as 

(1) 6.00 m 

(2) 5.99 m

(3) 5.95 m

(4) 5.90 m

What are the dimensions of the change in velocity?

(1) $\left[M^0{L}^0{T}^0\right]$

(2) $\left[L{T}^{-1}\right]$

(3) $\left[ML{T}^{-1}\right]$

(4) $\left[L{T}^{-2}\right]$

The dimensional formula for energy is  

(1) $\left[ML{T}^{-2}\right]$

(2) $\left[M{L}^2{T}^{-2}\right]$

(3) $\left[M^{-1}{L}^{2}T\right]$

(4) $\left[M L^2 T\right]$

The pair of the quantities having same dimensions is 

(1) Displacement, velocity 

(2) Time, frequency 

(3) Wavelength, focal length 

(4)  Force, acceleration 

The dimensional formula for relative refractive index is 

(1) $\left[M^1{L}^1{T}^1\right]$

(2) $\left[M^0{L}^0{T}^0\right]$

(3) $\left[M^1{L}^0{T}^0\right]$

(4) $\left[ML{T}^{-1}\right]$

The dimensional formula $\left[M{L}^{-1}{T}^{-2}\right]$ is for the quantity 

(1) Force  

(2) Acceleration 

(3) Pressure 

(4) Work 

The dimensionally correct expression for the resistance R among the following is 

[P=electric power, l= electric current, t=time 

V=voltage and E=electric energy]

(1) $R=\sqrt{Pl}$

(2) $R=\frac{E}{l^{2}t}$

(3) $R=V^{2}P$

(4) $R=vl$