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Electromagnets are made of soft iron because soft iron has

• low retenitivity and high coercive force

• high retentivity and high coercive force

• low retentivity and low coercive force

• low retentivity and low coercive force

In the given circuit the reading of voltmeter V₁ and V₂ are 300 V each. The reading to the voltmeter V₃ and ammeter A are respectively

• 150 V, 2.2 A

• 220 V , 2.2 A

• 220 V, 2.0 A

• 220 V, 2.0 A

A 220 V input is supplied to a transformer. The output circuit draws a current 2.0 A at 440 V. If the efficiency of the transformer is 80%, the current drawn by the primary windings of the transformer is 

• 3.6 A

• 2.8 A

• 2.5 A

• 2.5 A

A vibration magnetometer placed in magnetic meridian has a small bar magnet. The magnet executes oscillations with a time period of 2s in earth's horizontal magnetic field of 24 μT. When a horizontal field of 18 μT is produced opposite to the earth's field by placing a current-carrying wire, the new time period of magnet will be

• 1s

• 2s

• 3s

• 3s

Two positive ions, each carrying a charge q, are separated by a distance d. If F is the force of repulsion between the ions, the number of electrons missing from each ion will be (e being the charge on an electron)

The square surface of side L metre in the plane of the paper is placed in a uniform electric field E (volt/m) acting along the same place at angle θ with the horizontal side of the square as shown in the figure. The electric flux linked to the surface in unit of V-m is

• EL²

• EL² cos θ

• EL² sin θ

• EL² sin θ

A series combination of n₁ capacitors, each of value of C_1, is charged by a source of potential difference 4V. When another parallel combination of n₂ capacitors, each of value C_2, is charged by a source of potential difference V, it has the same (total) energy stored in it, as the first combination has. The value of C₂, in terms of C₁, is then

A square current carrying loop is suspended in a uniform magnetic field acting in the plane of the loop. If the force on one arm of the loop is , the net force on the remaining three arms of the loops is

• 3 

• -

• 
• 

Consider the following two statements

A) Kirchhoff junction law follows from the conservation of charge.

B) Kirchhoff's loop law follows from the conservation of energy

Which of the following is correct?

• Both (A) and (B) are wrong

• (A) Is correct and (B) is wrong

• (A) is wrong and (B) is correct

• (A) is wrong and (B) is correct

The mass of a  nucleus is 0.042u less than the sum of the masses of all its nucleons. The binding energy per nucleon is  nucleus is nearly

• 46 MeV

• 5.6 MeV

• 3.9 MeV

• 3.9 MeV