# B.sc. Math/Bio/B.Sc. Ag Practice Set-1, Model Papers UET 2018 BHU

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B.sc./B.Sc. Ag Practice Set-1, Model Papers UET 2018 BHU :

1. An electron is moving in a circular path under the influence of a transverse magnetic field of 3.57 × 10–2 T. If the value of e/m is 1.76 × 1011 C/kg, the frequency of revolution of the electron is?

2. A long wire carrying a steady current is bent into a circular loop of one turn. The magnetic field at the centre of the loop is B. It is then bent into a circular coil of n turns. The magnetic field at the centre of this coil of n turns will be

3. A galvanometer having a coil resistance of 100 Ω gives a full scale deflection, when a current of 1 mA is passed through it. The value of the resistance, which can convert this galvanometer into ammeter giving a full scale deflection for a current of 10 A,

A galvanometer of resistance 30Ω is connected to a battery of emf 2V with 1970Ω resistance in series. A full scale deflection of 20 divisions is obtained in the galvanometer. To reduce the deflection to 10 divisions, the resistance in series required is [MHT CET 2016]

5. In the cyclotron, as radius of the circular path of the charged particle increases (ω = angular velocity, v = linear velocity)

6. A proton is projected with a uniform velocity ‘v’ along the axis of a current carrying solenoid, then

7. A proton beam enters a magnetic field of 10–4 Wb m–2 normally. If the specific charge of the proton is 1011 C kg–1and its velocity is 10° ms–1, then the radius of the circle described will be [Karnataka CET 2015]

8. A rectangular coil of length 0.12 m and width 0.1 m having 50 turns of wire is suspended vertically in a uniform magnetic field of strength 0.2 Weber/m2. The coil carries a current of 2 A. If the plane of the coil is inclined at an angle of 30° with the direction of the field, the torque required to keep the coil in stable equilibrium will be [AIPMT 2015]

9. A proton and an alpha particle both enter a region of uniform magnetic field B, moving at right angles to the field B. If the radius of circular orbits for both the particles is equal and the kinetic energy acquired by proton is 1 MeV, the energy acquired by the alpha particle will be [AIPMT 2015]

10. In a region, steady and uniform electric and magnetic fields are present. These two fields are parallel to each other. A charged particle is released from rest in this region. The path of the particle will be a [AIEEE 2006]

11. Two concentric coils each of radius equal to 2π cm are placed right angles to each other. If 3A and 4A are the currents flowing through the two coils respectively. The magnetic induction (in Wb m–2) at the center of the coils will be

12. Two parallel wires 1 m apart carry currents of 1 A and 3 A respectively in opposite directions. The force per unit length acting between two wires is

13.  A cyclotron is used to accelerate

14. This question has Statement I and Statement II. Of the four choices given after the Statements, choose the one that best describes the two Statements[JEE Main 2013]

Statement – I : Higher the range, greater is the resistance of ammeter.

Statement – II : To increase the range of ammeter, additional shunt needs to be used across it.

15. A charged particle moves through a magnetic field perpendicular to its direction. Then [AIEEE 2007]

16. A galvanometer of resistance 50 Ω gives a full scale deflection for a current 5 × 10–4 A. The resistance that should be connected in series with the galvanometer to read 3 V is

17. Sensitivity of a moving coil galvanometer can be increased by

18. A range of galvanometer is ‘V’, when 50Ω resistance is connected in series. Its range gets doubled when 500Ω resistance is connected in series. Galvanometer resistance is

19. A circular loop of radius 0.3 cm lies parallel to a much bigger circular loop of radius 20 cm. The centre of the small loop is on the axis of the bigger loop. The distance between their centres is 15 cm. If a current of 2.0 A flows through the smaller loop, then the flux linked with bigger loop is

20. In cyclotron, for a given magnet, radius of the semicircle traced by positive ion is directly proportional to
(v = velocity of positive ion)

21. A current loop in a magnetic field

22. A galvanometer having internal resistance 10Ω requires 0.01 A for a full scale deflection. To convert this galvanometer to a voltmeter of full-scale deflection at 120V, we need to connect a resistance of

23. A charged particle experiences magnetic force in the presence of magnetic field. Which of the following statement is correct?

24. If a velocity has both perpendicular and parallel components while moving through a magnetic field, what is the path followed by a charged particle?

25.  A current I flows along the length of an infinitely long, straight, thin walled pipe. Then