Physics Objective (Multiple Choice) General Knowledge & General Science Questions & Answers for SSC-CGL, UPPSC, NDA, CDS and all one day examinations of India.
1. Edwin Howard Armstrong was an inventor of which of the following technologies?
[A] Television
[B] Compact Discs
[C] FM Radio
[D] Broadband
Show Answer
Correct Answer: C [FM Radio]
Notes:
Edwin Howard Armstrong was an American electrical engineer who developed FM radio and the superheterodyne receiver system. Edwin Howard Armstrong is the “father of FM radio” and was born in 1890.
2. With reference to a swinging pendulum, which among the following statements is correct when it is at bottom (middle of arc)?
[A] It has maximum kinetic energy and minimum potential energy
[B] It has maximum potential energy and minimum kinetic energy
[C] It has zero kinetic energy
[D] It has zero total energy
Show Answer
Correct Answer: A [ It has maximum kinetic energy and minimum potential energy]
Notes:
At the lowest point of its motion of swinging pendulum, kinetic energy is maximum and gravitational potential energy is minimum. At the highest point of its motion, kinetic energy is minimum and gravitational potential energy is maximum.
3. The spray bottles used as window or household cleaner or perfume spray works on:
[A] Capillary action
[B] Bernoulli’s Principle
[C] Pascal’s Law
[D] Stoke’s Law
Show Answer
Correct Answer: B [ Bernoulli’s Principle]
Notes:
When we press the top of bottle the pressure at top of the bottle decreases and hence, the velocity of liquid flow increases. Bernoulli’s Principle states that an increase in the speed of a fluid produces a decrease in pressure and that a decrease in the speed of a fluid produces an increase in pressure. The principle states that the total energy of a moving fluid remains constant at all times.
4. A projectile will achieve maximum horizontal range at which angle?
[A] 90°
[B] 60°
[C] 45°
[D] 30°
Show Answer
Correct Answer: C [45°]
Notes:
A projectile will achieve maximum horizontal range when it is projected at an angle of 45°. This concept of maximum horizontal range is used by athletes in long jump, javelin throw, cricket ball throw etc
5. What is the apparent weight of the person when the elevator is accelerating downwards?
[A] equal to the actual weight
[B] greater than the actual weight
[C] less than the actual weight
[D] 0
Show Answer
Correct Answer: C [less than the actual weight]
Notes:
The apparent weight of the person becomes less than the actual weight when the elevator is accelerating downwards. The apparent weight of the person becomes more than the actual weight when the elevator is accelerating upwards.
6. 1 kilogram force produces how much acceleration in a body of mass 1 kg?
[A] 1 ms-2
[B] 0
[C] 9.8 ms-2
[D] -1 ms-2
Show Answer
Correct Answer: C [9.8 ms-2]
Notes:
1 Kilogram force or 1 Kilogram weight is that much force which produces an acceleration of 9.8 ms-2 in a body of mass 1 kg. Also, 1 kg wt. or 1 kg f = 9.8 N
7. The energy by virtue of its position is known as:
[A] Kinetic energy
[B] Potential energy
[C] Internal energy
[D] Heat energy
Show Answer
Correct Answer: B [Potential energy]
Notes:
The energy by virtue of its position is known as Potential energy. The energy by virtue of its motion is known as Kinetic energy.
8. What is the gravitational potential energy for infinite distance?
[A] 0
[B] infinity
[C] 9.8 J
[D] None of the above
Show Answer
Correct Answer: A [0]
Notes:
The gravitational potential energy of a body at a point is defined as the amount of work done in bringing the body from infinity to that point against the gravitational force. U = – GMm/r When r =infinity, then U =0
9. Which of these represent the Angular momentum of a satellite?
[A] mvr
[B] ma
[C] mr
[D] mvh
Show Answer
Correct Answer: A [mvr]
Notes:
Angular momentum of satellite is given by mvr. Angular momentum of satellite depend on both the mass of orbiting and central body as well as the radius of orbit.
10. Which of the following has no effect on the pressure beneath the surface of a liquid?
[A] Area of the liquid surface
[B] Density of the liquid
[C] Strength of the gravitational field
[D] Depth of the liquid
Show Answer
Correct Answer: A [Area of the liquid surface]
Notes:
Pwater = ⍴gh It is clear from the above formula that water pressure only depends on density of water, gravitational acceleration and height of water column.
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