| ⇦ | 
| ⇨ |
An isolated sphere has a capacitance of 50pF. What would be the radius of the sphere?
Options
(a) 90cm
(b) 45cm
(c) 11.50cm
(d) 5.75cm
Correct Answer:
45cm
Explanation:
As potential of spherical charge (Q) having radius r is given by V = (1 / 4πε₀) (Q / r)
Also, capacitance, C = Q / V = Q / { (1 / 4πε₀) (Q / r)} C = 4πε₀r
If C = 50 × 10⁻¹² F, then
Radius of the sphere r = 50 × 10⁻¹² / 4πε₀
= 50 × 10⁻¹² × 9 × 10⁹
= 50 × 9 × 10⁻³
= 450 × 10⁻³ m
= 0.450 m = 45 cm
Related Questions: - An interference pattern was made by using red light. If the red light
- The magnetic lines of force inside a bar magnet
- The energy of groundstate (n=1) of hydrogen level is -13.6 eV. The ionistation
- A parallel plate capacitor with air between the plates has a capacitance of 9 pF.
- Two 220V – 100W bulbs are connected first in series and then in parallel.
Topics: Electrostatics
(146)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- An interference pattern was made by using red light. If the red light
- The magnetic lines of force inside a bar magnet
- The energy of groundstate (n=1) of hydrogen level is -13.6 eV. The ionistation
- A parallel plate capacitor with air between the plates has a capacitance of 9 pF.
- Two 220V – 100W bulbs are connected first in series and then in parallel.
Topics: Electrostatics (146)
Subject: Physics (2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
18000+ students are using NEETLab to improve their score. What about you?
Solve Previous Year MCQs, Mock Tests, Topicwise Practice Tests, Identify Weak Topics, Formula Flash cards and much more is available in NEETLab Android App to improve your NEET score.
Share this page with your friends
As Capacitance of Isolated sphere =4π€R
Given,
C=50picofarad
Then,
50×10(power -12)= 1/9×10(power9)×R
R=0.45m or 45cm….