1.	The dielectric constant of a metal is ?
	1
	-1
	0
	infinite
	Answer: infinite Explanation: The dielectric constant of metals is infinite. The dielectric constant of metal is infinite as the net electric field inside the metal is zero. The dielectric constant is defined as the ratio of the permittivity of a substance to the permittivity of free space.
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2.	Electric field in a cavity of metal ?
	is always zero
	depends upon the surroundings
	is not necessarily zero
	depends upon the size of cavity
	Answer: is not necessarily zero Explanation: is not necessarily zero
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3.	An electric field can deflect ?
	Gamma rays
	X-rays
	alpha particles
	neutrons
	Answer: alpha particles Explanation: Only charged particles can interact with electric field. X-rays are electromagnetic waves and are not charged. Neutrons are charge-less. Alpha particle are basically helium nuclei and are charged. So they are deflected in electric field.
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4.	A hemisphere is uniformly charged positively. The electric field at a point on a diameter away from the centre is directed ?
	at an angle tilted towards the diameter
	perpendicular to the diameter
	at an angle tilted away from the diameter
	parallel to the diameter
	Answer: perpendicular to the diameter Explanation: If the point is on a diameter away from the centre and a uniformly positive charged hemisphere is there, the electric field component parallel to diameter will be cancelled out. And perpendicular components will remain. So, an electric field will be perpendicular to the diameter at a point away from the centre on diameter.
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5.	A parrot comes and sits on a bare high power line. It will ?
	get killed instantaneously
	not be affected practically
	experience a strong shock
	experience a mild shock
	Answer: not be affected practically Explanation: A bird is not affected practically because both of its legs are at same potential thus, current cannot flow through its body.
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6.	If sphere of bad conductor is given charge then it is distributed on ?
	only inside the surface
	surface
	inside the surface
	None
	Answer: None Explanation:
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7.	Consider a region inside which, there are various types of charges but the total charge is zero. At points outside the region ?
	the work done to move a charged particle along a closed path, away from the region will not be zero.
	the electric field is necessarily zero.
	the electric field is due to the dipole moment of the charge distribution only.
	the dominant electric field is inversely proportional to r3, for large r (distance from origin).
	Answer: the dominant electric field is inversely proportional to r3, for large r (distance from origin). Explanation: When there are various types of charges in a region, but the total charge is zero, the region can be supposed to contain a number of electric dipoles. Therefore, at points outside the region, the dominant electric field directly proportional to1/r3 for large r.
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8.	Electric field lines provide information about ?
	direction
	nature of charge
	field strength
	all of these
	Answer: all of these Explanation: The electric field with high intensity has dense electric field lines. Thus, the electric field lines provide information about field strength, direction of electric field and nature of the electric charge.
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9.	A charge Q is divided into two parts of q and Q – q. If the coulomb repulsion between them when they are separated is to be maximum, the ratio of Q/q should be ?
	1:4
	4:1
	2:1
	1:2
	Answer: 2:1 Explanation: Let separation between two parts be r, then F = k.q(Q – q)/r² , For F to be maximum dF/dq = 0 then Q/q = 2/1 = 2 : 1
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10.	The Gaussian surface for calculating the electric field due to a charge distribution is ?
	A spherical surface
	Any closed surface around the charge distribution
	Any surface near the charge distribution
	A symmetrical closed surface at every point of which electric field has a single fixed value.
	Answer: For calculating electric field, a symmetrical closed surface at every point of which electric field has a single fixed value. Explanation: For calculating electric field, a symmetrical closed surface at every point of which electric field has a single fixed value.
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