The energy required to break one bond in DNA is \(10^{-20}~\text{J}\). This value in eV is nearly:
1. \(0.6\)
2. \(0.06\)
3. \(0.006\)
4. \(6\)
Dimensions of stress are:
1. | \( {\left[{ML}^2 {T}^{-2}\right]} \) | 2. | \( {\left[{ML}^0 {T}^{-2}\right]} \) |
3. | \( {\left[{ML}^{-1} {T}^{-2}\right]} \) | 4. | \( {\left[{MLT}^{-2}\right]}\) |
The dimensions of pressure are the same as that of
(1) Energy
(2) Energy per unit area
(3) Force per unit area
(4) Force per unit volume
Time intervals measured by a clock give the following readings: \(1.25\) s, \(1.24\) s, \(1.27\) s, \(1.21\) s, and \(1.28\) s. What is the percentage relative error of the observations?
1. \(2\)%
2. \(4\)%
3. \(16\)%
4. \(1.6\)%
A calorie is a unit of heat (energy in transit) and it equals about \(4.2~\text{J}\) where \(1~\text{J}= 1~\text{kg-m}^2\text{s}^{-2}\). Suppose we employ a system of units in which the unit of mass equals \(\alpha~\text{kg}\) the unit of length equals \(\beta~\text{m}\), and the unit of time is \(\gamma~\text{s}\) then the magnitude of calories in terms of new units is:
1. \(4.2\alpha^{-2}\beta^{-2}\gamma^{2}\)
2. \(4.2\alpha^{2}\beta^{-2}\gamma^{2}\)
3. \(4.2\alpha^{-1}\beta^{-2}\gamma^{2}\)
4. \(4.2\alpha^{-1}\beta^{2}\gamma^{-2}\)
Which of the following is the most precise device for measuring length?
1. | a vernier calliper with \(20\) divisions on the sliding scale. |
2. | a screw gauge of pitch \(1\) mm and \(100\) divisions on the circular scale. |
3. | an optical instrument that can measure the length within a wavelength of light. |
4. | both (1) and (2) |
The number of significant figures in \(0.0006032~\text m^2\) is:
1. | \(4 \) | 2. | \(5\) |
3. | \(7\) | 4. | \(3\) |
A physical quantity \(P\) is related to four observables \(a,\) \(b,\) \(c,\) and \(d\) as follows; \(P=\frac{a^{3}b^{2}}{\sqrt{c}d}.\)
The percentage errors of measurement in \(a,\) \(b,\) \(c,\) and \(d\) are 1%, 3%, 4% and 2%, respectively. Then the percentage error in the quantity \(P\) is:
1. 12%
2. 13%
3. 14%
4. 15%
When the planet Jupiter is at a distance of 824.7 million kilometres from the Earth, its angular diameter is measured to be 35.72” of arc. Then the diameter of Jupiter is: