wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

Three point charges, 1 C, 2 C and 3 C are placed at the corners of an equilateral triangle of side 100 cm. Find the work done to move these charges to corners of similar triangle of side 50 cm.

A
1012 J
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
1011 J
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C
1013 J
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
1010 J
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is B 1011 J
Given that,
Charge, q1 = 1 C
Charge, q2 = 2 C
Charge, q3 = 3 C
Distance between them, r= 100 cm = 1 m

Case I: When charges are placed on the corner of triangle having side 1 m.

The potential energy of the system will be,
U1 = kr{q1q2+q2q3+q1q3}
U1= k{2+6+3}
U1= 11k= 11×9×109
U1= 9.9×1010 J1011 J (i)

Case II: When charges are moved to corner of triangle having side r=0.5 m

The potential energy of the system will be,
U2 = kr{q1q2+q2q3+q1q3}
U2= kr {2+6+3}
U2= k0.5 {11}
U2= 2k×11=2×11×9×109
U2= 19.8×1010 J2×1011 J(ii)

The work done to move the charges will be,
W=U2 U1
W= (21)×1011 J
W= 1011 J

Hence, option (a) is correct.

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Electric Field inside a Conductor
PHYSICS
Watch in App
Join BYJU'S Learning Program
CrossIcon