11th class (Fsc) Physics unit 5 MCQs
100. Weight of a 60 kg man in moving elevator (downward) with constant acceleration of 1/4g(g =10ms-2)
a. 600 N
b. Zero
c. 200 N
d. 300 N
101. A 60 kg man in an elevator is moving upward with an acceleration of 93.8 ms_2 The apparent weight of the man:
a. Remain constant
b. Increases
c. Becomes zero
d. Decreases
102. An elevator is moving up with acceleration equal to ‘g’. an apparent weight of the body in an elevator is:
a. 2mg
b. zero
c. 3mg
d. Equal to real weight
103. If a body of mass 10kg is falling freely. Its apparent weight is:
a. 10 N
b. zero
c. 980 N
d. 98 N
104. The apparent weight of a pilot diving down with acceleration 9.8ms-2 will becomes:
a. Double
b. Half
c. Increases to four times
d. zero
105. The weight of an object in an elevator moving down with an acceleration of 9.8m/s2 will becomes:
a. Unchanged
b. Half
c. zero
d. Double
106. A man in a lift is moving upward with constant velocity will conclude that his weight has:
a. Reduced to zero
b. Increase
c. Not changed
d. Decreased
107. The ratio between orbital and escape velocities are:
a. √1/2
b. 1
c. √2
d.1/2
108. The expression for the orbital velocity of satellite is given by:
a. v= √GM /r
b. v= √GMr
c. v= √r /GM
d. v= √GM
109. Relation between escape velocity ‘Vesc and orbital velocity ‘vesc ’ is:
a. Vesc = Vo
b. Vesc = 1/2Vo
c. Vesc = 2Vo
d. Vesc = √2Vo
110. An orbital speed of a satellite can be determined by the equation:
a. √gR
b. √2gR
c. √GM/R
d. √2GM/R
111. Orbital velocity near surface of earth is given by:
a. √2g/R
b. √2gR
c. √g/R
d. √gR
112. The frequency of rotation of a spaceship about its own axis to create artificial gravity like that on earth is:
a. f= 1/2π√g/R2
b. f= 2π√g/R
c. f= 1/2π√R/g
d. f= 1/2π√g/R
113. The height of the geostationary satellite above the equator is:
a. 34000 km
b. 35000 km
c. 33000 km
d. 36000 km
114. The mass of earth is equal to:
a. 6×1020Kg
b. 6×1024Kg
c. 5×1020Kg
d. 5×1024Kg
115. Height of geo-stationary orbit the satellite above the earth is:
a. 400 km
b. 300 km
c. 250 km
d. None of these
116. The period of revolution of a geostationary satellites is:
a. 1 day
b. 1 hours
c. 1 month
d. 48 min
117. The min-number of communication satellite required to cover whole earth is:
a. 5
b. 4
c. 2
d.3
118. One geo stationary satellite covers longitudinal angle:
a. 90o
b. 270o
c. 60o
d. 120o
119. A communication satellite is used to reflect the signal of:
a. y-rays
b. Microwaves
c. x-rays
d. Radio waves
120. The minimum number of correctly positioned communication satellites to cover whole populated earth is:
a. 100
b. 3
c. 200
d. 2
121. the largest satellite system is managed by:
a. 136 countries
b. 116 countries
c. 140 countries
d. 126 countries
122. Microwave frequencies used in satellite for communication are:
a. 4,6,8 and 12 Hz
b. 4,6,8 and 10 Hz
c. 4,8,11 and 16GHz
d. 4,6,11 and 14 GHz
123. How many closed orbiting satellites form the Global positioning system?
a. 24
b. 3
c. 22
d. 12
124. International telecommunication satellite organization operates at microwave frequencies of:
a. 4,6,8, and 12Hz
b. 4,6,8, and 10Hz
c. 4,8,11, and 11GHz
d. 4,6,8, and 14GHz
125. Einstein’s theory gives us a physical picture of how the:
a. Moment of inertia produced
b. Body moves
c. Weightlessness creates
d. Gravity works
126. The law of gravitation was introduced by:
a. Newton
b. Huygen
c. Pascal
d. Boyle
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