# Physics (Test 4)

## Under Graduate Entrance Exams : Neet Entrance Exam

| Home | | Under Graduate Entrance Exams | | Neet Entrance Exam | | Physics | Physics
| Physical World | | Units and Measurements | | Motion in A Straight Line | | Motion in A Plane | | Laws of Motion | | Work Energy and Power | | System of Particles and Rotational Motion | | Gravitation | | Mechanical Properties of Solids | | Mechanical Properties of Fluids | | Thermal Properties of Matter | | Thermodynamics | | Kinetic Theory | | Oscillations | | Waves | | Electric Charges and Fields | | Electrostatic Potential and Capacitance | | Current Electricity | | Moving Charges and Magnetism | | Magnetism and Matter | | Electromagnetic Induction | | Alternating Current | | Electromagnetic Waves | | Ray Optics and Optical Instruments | | Wave Optics | | Dual Nature of Radiation and Matter | | Atoms | | Nuclei | | Electronic Devices | | Communication Systems | | UNIT I: Nature of Physical World and Measurement | | UNIT II: Kinematics | | UNIT III: Laws of motion | | UNIT IV: Work, Energy and Power | | UNIT V: Motion of System of Particles and Rigid Bodies | | Unit I: Electrostatics | | Unit II: Current Electricity | | Unit III: Magnetism and magnetic effects of electric current | | Unit IV: Electromagnetic Induction And Alternating Current | | Unit V: Electromagnetic waves |
Q.1
Which of the following are false for electromagnetic waves
A. transverse
B. mechanical waves
C. longitudinal
D. produced by accelerating charges
Explaination / Solution:
No Explaination.

Workspace
Report
Q.2
Which of the following is NOT true for electromagnetic waves?.
A. it transport energy
B. it transport momentum
C. it transport angular momentum
D. in vacuum, it travels with different speeds which depend on their frequency
Explaination / Solution:
No Explaination.

Workspace
Report
Q.3
In an electrical circuit, R, L, C and AC voltage source are all connected in series. When L is removed from the circuit, the phase difference between the voltage and current in the circuit is π /3 . Instead, if C is removed from the circuit, the phase difference is again π / 3 . The power factor of the circuit is
A. 1 / 2
B. 1/ √2
C. 1
D. √3 / 2
Explaination / Solution: Workspace
Report
Q.4
A circular coil of radius 5 cm and 50 turns carries a current of 3 ampere. The magnetic dipole moment of the coil is
A. 1.0 amp – m2
B. 1.2 amp – m2
C. 0.5 amp – m2
D. 0.8 amp – m2
Explaination / Solution: Workspace
Report
Q.5
A flat dielectric disc of radius R carries an excess charge on its surface. The surface charge density is σ. The disc rotates about an axis perpendicular toits plane passing through the center with angular velocity ω. Find the magnitude of the torque on the disc if it is placed in a uniform magnetic field whose strength is B which is directed perpendicular to the axis of rotation
A. B. C. D. Explaination / Solution: Workspace
Report
Q.6
In a large building, there are 15 bulbs of 40W, 5 bulbs of 100W, 5 fans of 80W and 1 heater of 1kW are connected. The voltage of electric mains is 220V. The minimum capacity of the main fuse of the building will be
A. 14 A
B. 8 A
C. 10 A
D. 12 A
Explaination / Solution: Workspace
Report
Q.7
An electric dipole is placed at an alignment angle of 30º with an electric field of 2 × 105 N C-1. It experiences a torque equal to 8 N m. The charge on the dipole if the dipole length is 1 cm is
A. 4 mC
B. 8 mC
C. 5 mC
D. 7 mC
Explaination / Solution: Workspace
Report
Q.8
Three capacitors are connected in triangle as shown in the figure. The equivalent capacitance between the points A and C is A. 1µF
B. 2 µF
C. 3 µF
D. 1/4µF
Explaination / Solution: Workspace
Report
Q.9
Two discs of same moment of inertia rotating about their regular axis passing through center and perpendicular to the plane of disc with angular velocities ω1 and ω2. They are brought in to contact face to face coinciding the axis of rotation. The expression for loss of energy during this process is,
A. 1/4 I (ω1- ω2)2
B. I (ω1- ω2)2
C. 1/8 I (ω1- ω2)2
D. 1/2 I (ω1- ω2)2
Explaination / Solution:
No Explaination.

Workspace
Report
Q.10
What is the minimum velocity with which a body of mass m must enter a vertical loop of radius R so that it can complete the loop?
A. √(2gR)
B. √(3gR)
C. √(5gR)
D. √(gR)