Deck 10: Physics Forces, Moments, and Gravitational Fields

Question 1

Output current from an LED is

A)20 mA
B)30 mA
C)40 mA
D)50 mA

Answer 1

20 mA

Question 2

In an inverting amplifier the non-inverting input (+) is connected to

A)1 V line
B)0 V line
C)2 V line
D)3 V line

Answer 2

0 V line

Question 3

Actual op-amp may have an open loop gain of{{}}

A)102
B)105
C)103
D)104

Answer 3

105

Question 4

Coil of relay is connected to the

A)input of op-amp
B)output of op-amp
C)midpoint of op-amp
D)anywhere in between input and ouput of op-amp

Question 5

Pair of forces that cause steering wheel of a car to rotate is called

A)couple
B)friction
C)normal force
D)weight

Question 6

If the principle of moments for any object holds, then object is in state of

A)inertia
B)equilibrium
C)suspension
D)motion

Question 7

Combined effect of several forces is known as

A)net force
B)resultant force
C)normal force
D)weight

Question 8

To form a couple, the force should be

A)equal in magnitude
B)parallel and opposite
C)separated by distance
D)all of above

Question 9

Moment of force depends upon

A)magnitude of force
B)perpendicular distance of force from pivot
C)both A and B
D)axis of rotation

Question 10

Two perpendicular components are

A)independent of each other
B)dependent on each other
C)anti parallel to each other
D)parallel to each other

Question 11

Object is in equilibrium if resultant force acting on it is

A)increasing
B)decreasing
C)zero
D)becomes constant

Question 12

Center of gravity of an irregular body lies on the

A)edge
B)center of body
C)point of intersection of lines
D)along the axis of rotation

Question 13

Number of forces a falling tennis ball experiences is

A)1
B)3
C)2
D)4

Question 14

Point where all weight of object acts is called

A)central point
B)center of gravity
C)edge
D)center of mass

Question 15

If weight of a falling tennis ball is 1.0 N and drag force acting on it is 0.2 N then resultant force is

A)0.8 N
B)0.5 N
C)1 N
D)2 N

Question 16

If the resultant vector forms an angle of 45°, then the two components are

A)parallel to each other
B)perpendicular to each other
C)anti parallel to each other
D)anti perpendicular to each other

Question 17

Force acting on two point masses is directly proportional to

A)sum of masses
B)difference of masses
C)distance between masses
D)product of masses

Question 18

Mass of Earth when it's radius is 6400 km and gravitational field strength is 9.81 N kg ^-1 is {{}}

A)6.0 × 10²⁴ kg
B)5 × 10²³ kg
C)40 × 10⁹ kg
D)9 × 10²⁴ kg

Question 19

On scale of building, gravitational field is

A)increasing
B)decreasing
C)uniform
D)varying

Question 20

Decrease in field strength on top of Mount Everest is

A)10%
B)5%
C)1%
D)0.3%

Question 21

Work done on an object to bring it to certain point in space is called

A)gravitational potential energy
B)potential energy
C)kinetic energy
D)mechanical energy

Question 22

N kg-1is equivalent to{{}}

A)m s^-2
B)m s^-1
C)m s
D)m s^-3

Question 23

Mass of satellite orbiting Earth is

A)considered
B)irrelevant
C)should be infinite
D)should be zero

Question 24

Spacing between field lines indicates

A)direction of field lines
B)strength of field lines
C)magnitude of field lines
D)work done by field lines

Question 25

Square of orbital period is proportional to

A)radius
B)square of radius
C)cube of radius
D)square of diameter