(a) How many astronomical units (A.U.) make 1 parsec?

(b) Consider a sunlike star at a distance of 2 parsecs. When it is seen through a telescope with 100 magnification, what should be the angular size of the star? Sun appears too be (1/2)° from the earth. Due to atmospheric fluctuations, eye can’t resolve objects smaller than 1 arc minute.

(c) Mars has approximately half of the earth’s diameter. When it is closest to the earth it is at about 1/2 A.U. from the earth. Calculate what size it will appear when seen through the same telescope.

0 5 Views | Posted 3 months ago
Asked by Shiksha User

  • 1 Answer

  • P

    Answered by

    Payal Gupta | Contributor-Level 10

    3 months ago

    This is a long answer type question as classified in NCERT Exemplar

    (a) 1 parsec =distance at which 1AU long arc subtends an angle of 1sec

    1parsec = ( 1 A U 1 a r c s e c )

    1 deg = 3600 arc sec

    1 parsec = π 3600 × 180 r a d

    1parsec = 3600 × 180 π A U = 2 × 10 5 A U

    (b) sun’s diameter is 1/20

    so at 1 parsec star is 1 / 2 2 × 10 5  degree in diameter= 15 × 10-5 arc/min with magnification it looks like 15 × 10-3

    (c) D m a r s D e a r t h = 1 2

    we know that D e a r t h D s u n = 1 100

    D m a r s D s u n = 1 2 × 1 100

    At 1AU sun’s diameter =1/20

    Mars diameter = 1 2 × 1 200 = 1 400

    AT 1/2AU

     Mars diameter will 1/2000 but with hundred magnification it is 1/20

Similar Questions for you

V
Vishal Baghel

According to question, we can write

Total moles of gas = n = nOxygen + nOxygen = 1 6 2 + 1 2 8 3 2 = 1 2 m o l e s  

Volume of gas = 12 × 22.4 litre = 268.8 litre = 2.688 × 105 cm3 2 7 × 1 0 4 c m 3  

V
Vishal Baghel

K = Q r Δ x Δ A T

M L 2 T - 2 ( L ) L 2 ( θ ) ( T ) M 1 L 1 - T - 3 θ - 1

V
Vishal Baghel

Viscosity = Pascal . Second

P X A Y T Z = [ M 1 L 1 T 1 ]        

[ M 1 L + 1 T 1 ] x [ L 2 ] y [ T 1 ] z = M 1 L 1 T 1

= x = 1,     x + 2y = -1,      -x + z = 1

y = -1,              Z = 0

Viscosity = [P1A-1T0]

P
Payal Gupta

1 msD = 1mm

10 vsD = 9msD

1vsD = 0.9 MsD

L.C. = 1MSD – 1VSD = 1 – 0.9 = 0.1 mm

Zero error = 4LC = 0.4 mm

Reading = MSR + VSR + correction

= 4.1 cm + 6 * .01 cm + (-0.04 cm) = (4.1 + 0.06 – 0.04) cm

= 4.12 cm = 412 * 10-2 cm

V
Vishal Baghel

Δ Q = m s Δ T s = Δ Q m Δ T [ s ] = M L 2 T 2 M Q = L 2 T 2 Q 1

Δ Q = m L [ L ] = M L 2 T 2 M = L 2 T 2

Get authentic answers from experts, students and alumni that you won't find anywhere else

Sign Up on Shiksha

On Shiksha, get access to

  • 65k Colleges
  • 1.2k Exams
  • 688k Reviews
  • 1800k Answers

Learn more about...

Share Your College Life Experience

Didn't find the answer you were looking for?

Search from Shiksha's 1 lakh+ Topics

or

Ask Current Students, Alumni & our Experts

×
×

This website uses Cookies and related technologies for the site to function correctly and securely, improve & personalise your browsing experience, analyse traffic, and support our marketing efforts and serve the Core Purpose. By continuing to browse the site, you agree to Privacy Policy and Cookie Policy.

Need guidance on career and education? Ask our experts

Characters 0/140

The Answer must contain atleast 20 characters.

Add more details

Characters 0/300

The Answer must contain atleast 20 characters.

Keep it short & simple. Type complete word. Avoid abusive language. Next

Your Question

Edit

Add relevant tags to get quick responses. Cancel Post