Releted MCQ Question on
Electrostatics and Magnetism >> Electric Charges
Releted Question 1
Three charges $$Q, + q$$ and $$ + q$$ are placed at the vertices of a right-angled isosceles triangle as shown. The net electrostatic energy of the configuration is zero if $$Q$$ is equal to
Three charges $$Q, + q$$ and $$ + q$$ are placed at the vertices of a right-angled isosceles triangle as shown. The net electrostatic energy of the configuration is zero if $$Q$$ is equal to
A.
$$\frac{{ - q}}{{1 + \sqrt 2 }}$$
B.
$$\frac{{ - 2q}}{{2 + \sqrt 2 }}$$
C.
$$ - 2q$$
D.
$$ + q$$
Releted Question 2
Two equal point charges are fixed at $$x = - a$$ and $$x = + a$$ on the $$x$$-axis. Another point charge $$Q$$ is placed at the origin. The change in the electrical potential energy of $$Q,$$ when it is displaced by a small distance $$x$$ along the $$x$$-axis, is approximately proportional to
A.
$$x$$
B.
$${x^2}$$
C.
$${x^3}$$
D.
$$\frac{1}{x}$$
Releted Question 3
Six charges of equal magnitude, 3 positive and 3 negative are to be placed on $$PQRSTU$$ corners of a regular hexagon, such that field at the centre is double that of what it would have been if only one $$+ve$$ charge is placed at $$R.$$ Which of the following arrangement of charge is possible for $$P,Q,R,S,T$$ and $$U$$ respectively.
Six charges of equal magnitude, 3 positive and 3 negative are to be placed on $$PQRSTU$$ corners of a regular hexagon, such that field at the centre is double that of what it would have been if only one $$+ve$$ charge is placed at $$R.$$ Which of the following arrangement of charge is possible for $$P,Q,R,S,T$$ and $$U$$ respectively.
A.
$$+,+,+,-,-,-$$
B.
$$-,+,+,+,-,-$$
C.
$$-,+,+,-,+,-$$
D.
$$+,-,+,-,+,-$$
Releted Question 4
A long, hollow conducting cylinder is kept coaxially inside another long, hollow conducting cylinder of larger radius. Both the cylinders are initially electrically neutral.
A.
A potential difference appears between the two cylinders when a charge density is given to the inner cylinder.
B.
A potential difference appears between the two cylinders when a charge density is given to the outer cylinder.
C.
No potential difference appears between the two cylinders when a uniform line charge is kept along the axis of the cylinders.
D.
No potential difference appears between the two cylinders when same charge density is given to both the cylinders.