The angle of \(1^\circ\) (degree) will be equal to:
(Use \(360^\circ=2\pi\) rad)
1. \(1.034\times10^{-3}\) rad
2. \(1.745\times10^{-2}\) rad
3. \(1.524\times10^{-2}\) rad
4. \(1.745\times10^{3}\) rad

A man wishes to estimate the distance of a nearby tower from him. He stands at point A in front of tower C and spots a very distant object O in line with AC. He then walks perpendicular to AC up to B, a distance of 100 m, and looks at O and C again. Since O is very distant, the direction BO is practically the same as AO; but he finds the line of sight of C shifted from the original line of sight by an angle \(\theta=40^\circ\) (\(\theta\) is known as ‘parallax’), the distance of the tower C from his original position A is: (Given \(\tan40^\circ=0.8391\))
1. 119 m
2. 126 m
3. 320 m
4. 219 m

The moon is observed from two diametrically opposite points A and B on Earth. The angle θ subtended at the moon by the two directions of observation is $1°$ 54′. Given the diameter of the Earth to be about 1.276 × ${10}^7$ m, the distance of the moon from the Earth is:

$\left(1\right) 2.91\times {10}^8 \mathrm{m}$
$\left(2\right) 3.11\times {10}^9 \mathrm{m}$
$\left(3\right) 3.84\times {10}^8 \mathrm{m}$
$\left(4\right) 1.91\times {10}^7 \mathrm{m}$

The Sun’s angular diameter is measured to be 1920′′. The distance D of the Sun from the Earth is $1.496\times {10}^{11} \mathrm{m}.$ The diameter of the Sun:

1.  $2.39\times {10}^9 \mathrm{m}$

2.  $0.39\times {10}^9 \mathrm{m}$

3.  $1.39\times {10}^9 \mathrm{m}$

4.  $1.39\times {10}^{10} \mathrm{m}$

If the size of a nucleus (in the range of \(10^{-15}\) to \(10^{-14}\) m) is scaled up to the tip of a sharp pin, what roughly is the size of an atom? Assume tip of the pin to be in the range \(10^{-5}\) m to \(10^{-4}\) m.
1. \(1\) m
2. \(10\) m
3. \(10^{-10}\) m
4. \(10^{-5}\) m

We measure the period of oscillation of a simple pendulum. In successive measurements, the readings turn out to be 2.63 s, 2.56 s, 2.42 s, 2.71 s, and 2.80 s. The average absolute error and percentage error, respectively, are:

1.  0.22 s and 4%

2.  0.11 s and 4%

3.  4 s and 0.11%

4.  5 s and 0.22%