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A circular loop of radius R carrying current I lies in the X – Y plane with its centre at the origin. The total magnetic flux through the x – y plane is…..

a) Directly proportional to I b) Directly proportional to R c) Directly proportional to R2 d) zero Answer: d) zero Solution: A circular... View Article

When a train travels with a speed of 360 km h^–1 along the track separated by 1 meter. The vertical component of the earth’s magnetic field is 0.1 × 10^–4 T. What is the value of induced emf between the rails?

a) 10-2 V b) 10-4 V c) 10-3 V d) 1 V Answer: c) 10-3 V Solution: Velocity of the train =... View Article

A transformer of efficiency 90% draws an input power of 4 kW. An electrical appliance connected across the secondary draws a current of 6 A. The impedance of the device is………

a) 60 Ω b) 50 Ω c) 80 Ω d) 100 Ω Answer: d) 100 Ω Solution: Impedance, η =... View Article

A circular coil of diameter 21 cm is placed in a magnetic field of induction 10^-4 T. The magnitude of flux linked with the coil, when the plane of coil makes an angle 30° with the field is

a) 1.44 x 10-6 Wb b) 1.732 x 10-6 Wb c) 3.1 x 10-6 Wb d) 4.2 x 10-6 Wb Answer: b) 1.732 x 10-6 Wb Solution: \(\begin{array}{l}\phi = \vec{B}.\vec{a}... View Article

When a circular coil of radius 1 m and 100 turns is rotated in a horizontal uniform magnetic field, the peak value of emf induced is 100 V. The coil is unwound and then rewound into a circular coil of radius 2 m. If it is rotated now, with the same speed, under similar conditions, the new peak value of emf developed is

a) 50 V b) 25 V c) 100 V d) 150 V e) 200 V Answer: e) 200 V Solution: e... View Article

A rectangular loop of sides 10 cm and 5 cm with a cut is stationary between the pole pieces of an electromagnet. The magnetic field of the magnet is normal to the loop. The current feeding the electromagnet is reduced so that the field decreased from its initial value of 0.3 T at the rate of 0.02 T/s. If the cut is joined and the loop has a resistance of 2.0 Ω, the power dissipated by the loop as heat is

a) 5 nW b) 4 nW c) 3 nW d) 2 nW Answer: a) 5 nW Solution: Area, A = 10... View Article

There is a uniform magnetic field directed perpendicular and into the plane of the paper. An irregular shaped conducting loop is slowly changing into a circular loop in the plane of the paper. Then

a) current is induced in the loop in the anticlockwise direction b) current is induced in the loop in the clockwise... View Article

For a set A, consider the following statements:

For a set A, consider the following statements: 1. A⋃P(A) = P(A) 2. {A}⋂ P(A) = A 3. P(A)-{A} =... View Article

Consider the following statements.

Consider the following statements. I.If An is the set of first n prime numbers, Then Un=210 An is equal to... View Article

Which of the following is correct?

Which of the following is correct? 1. n(S ⋃ T) is maximum when n (S ∩ T) is least. 2.... View Article

Out of 32 persons, 30 invest in national savings certificates and 17 invest in shares. What is the number of persons who invest in both?

(a) 13 (b) 15 (c) 17 (d) 19 Solution: Let A be the set of people invested in national savings... View Article

In a group of 50 people, two tests were conducted, one for diabetes and one for blood pressure. 30 people were diagnosed with diabetes and 40 people were diagnosed with high blood pressure. What is the minimum number of people who were having diabetes and high blood pressure?

(a) 0 (b) 10 (c) 20 (d) 30 Solution: Let A be the set containing people diagnosed with diabetes and... View Article

There are 600 students in a school. If 400 of them can speak Telugu, 300 can speak Hindi, then the number of students who can speak both Telugu and Hindi is:

(a) 100 (b) 200 (c) 300 (d) 400 Solution: Let A = set of students speaking Telugu B = set... View Article

If the cardinality of a set A is 4 and that of a set B is 3, then what is the cardinality of the set AΔ B?

(a) 1 (b) 5 (c) 7 (d) Cannot be determined as the sets A and B are not given Solution:... View Article

If A and B are two disjoint sets, then which one of the following is correct?

(a) A-B = A-(A⋂B) (b) B-A = A⋂B (c) A⋂B = (A⋃B) (d) none of these Solution: Given that A... View Article

Which of the following is/are true?

Which of the following is/are true? 1. If A is a subset of the universal set U, then its complement... View Article

The cardinality of the set P{P[P(Ø)]} is

(a) 0 (b) 1 (c) 2 (d) 4 Solution: The number of elements in a set is called the cardinality... View Article

In a B School, there are 15 teachers who teach marketing or finance. Of these, 8 teach finance and 4 teach both marketing and finance. How many teach marketing but not finance?

(a) 15 (b) 20 (c) 11 (d) None of these Solution: Let F denote Finance and M represent Maths. n(F⋃M)... View Article

A survey shows that 61%, 46%, and 29% of the people watched “3 idiots”, “Rajneeti” and “Avatar” respectively. 25% of people watched exactly two of the three movies and 3% watched none. What percentage of people watched all three movies?

(a) 39% (b) 11% (c) 14% (d) 7% Solution: Let A represent the people who watched ‘3 idiots’, B represents... View Article

If X and Y are two sets such that (X ⋃ Y) has 60 elements, X has 38 elements and Y has 42 elements, how many elements do (X ⋂ Y) have?

(a) 11 (b) 20 (c) 13 (d) None of these Solution: Given n (X ⋃ Y) = 60 n(X) =... View Article

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