161- Which surface has greater magnetic flux in same magnetic field, each has an area 1 m².
A. Circular
B. Rectangular
C. Triangular
D. All have same flux
View Answer
Answer : D. All have same flux
Description
162- A charged particle is moving in a uniform magnetic field. For the motion of the particle due to the field, which quantity has a constant non-zero value?
A. acceleration
B. displacement
C. rate of change of acceleration
D. velocity
View Answer
Answer : D. velocity
Description
163- The magnetic field inside a solenoid is:
A. Zero
B. Uniform
C. Non-uniform
D. Strong at the ends
View Answer
Answer : B. Uniform
Description
164- The magnetic field of a current carrying conductor is due to:
A. motion of electrons
B. motion of protons
C. motion of neutrons
D. motion of ions
View Answer
Answer : A. motion of electrons
Description
165- A transformer has 100 turns in the primary coil and 200 turns in the secondary coil. The primary coil is connected to a 6 V battery. The voltage in the secondary coil would be:
A. 3 V
B. 6 V
C. 9 V
D. 12 V
View Answer
Answer : D. 12 V
Description
166- A step up transformer has a turn ratio of 1:100. An alternating voltage of amplitude 20 V is connected to the primary. The amplitude of secondary voltage is:
A. 2 V
B. 20 V
C. 200 V
D. 2000 V
View Answer
Answer : D. 2000 V
Description
167- Which of the following is the SI unit of magnetic induction?
A. Tesla
B. Weber
C. Henry
D. Gauss
View Answer
Answer : A. Tesla
Description
168- When a charged particle moves in a magnetic field, its kinetic energy:
A. increases
B. decreases
C. remains constant
D. becomes zero
View Answer
Answer : C. remains constant
Description
169- A 100 W lamp is operated by 240 V a.c mains. The peak value of current is:
A. 0.42 A
B. 0.59 A
C. 0.72 A
D. 1.18 A
View Answer
Answer : B. 0.59 A
Description
170- The value of alternating current is measured by:
A. hot wire ammeter
B. moving coil galvanometer
C. tangent galvanometer
D. ballistic galvanometer
View Answer
Answer : A. hot wire ammeter
Description
171- The value of current at resonance in RLC series circuit is:
A. maximum
B. minimum
C. zero
D. infinite
View Answer
Answer : A. maximum
Description
172- The velocity of light was determined accurately by:
A. Newton
B. Roemer
C. Huygens
D. Michelson
View Answer
Answer : D. Michelson
Description
173- The speed of light in vacuum is:
A. 3 × 10⁶ m/s
B. 3 × 10⁵ m/s
C. 3 × 10⁸ m/s
D. 3 × 10¹⁰ m/s
View Answer
Answer : C. 3 × 10⁸ m/s
Description
174- The critical angle for a beam of light passing from a diamond into the air is 24.4°. This means that any light rays that strike the surface interface at an angle greater than 24.4° will be:
A. completely reflected
B. partially reflected and partially refracted
C. completely absorbed
D. completely transmitted
View Answer
Answer : A. completely reflected
Description
175- The refractive index of water is 1.33. What will be the speed of light in water?
A. 3 × 10⁸ m/s
B. 2.26 × 10⁸ m/s
C. 4 × 10⁸ m/s
D. 1.33 × 10⁸ m/s
View Answer
Answer : B. 2.26 × 10⁸ m/s
Description
176- A convex lens has a focal length f. An object is placed at a distance between f and 2f on a line perpendicular to the center of the lens. The image formed is located at what distance from the lens?
A. between f and 2f
B. between 2f and infinity
C. between the lens and f
D. at 2f
View Answer
Answer : B. between 2f and infinity
Description
177- A lens has a power of +5 diopters. What is the focal length of the lens?
A. 0.2 m
B. 0.5 m
C. 2 m
D. 5 m
View Answer
Answer : A. 0.2 m
Description
178- In Young's double slit experiment, the fringe spacing for light of wavelength 500 nm is 2.0 mm. The fringe spacing becomes 1.0 mm when the wavelength of light used is changed to:
A. 250 nm
B. 500 nm
C. 750 nm
D. 1000 nm
View Answer
Answer : A. 250 nm
Description
179- The resolving power of a telescope can be increased by increasing the:
A. focal length of the objective
B. focal length of the eyepiece
C. aperture of the objective
D. aperture of the eyepiece
View Answer
Answer : C. aperture of the objective
Description
180- An electron of charge e coulomb passes through a potential difference of V volts. Its energy in joules will be: