Use the following to answer question 46 I . increase the current

II. use a stronger magnet

III. use thicker wire

IV. reverse the battery

V. add more coils of wire inside the magnet

46. To increase the force with which the wire is pushed when the switch is closed, which of
the following things could be done?

a. I and II only
b. II, III, and IV only
C. II and IV only
d. I, II and V only

47. A group of students had built a homemade motor and were in the process of trying to
test it. When they hooked it up to their battery they found that the wires in their coil got hot, but the coil would not turn. Of the following solutions, which would be their best
course of action to make the motor spin?

a. add more wire to the coil

b. use a stronger magnet

C. use a higher voltage battery

d. plug into an AC source

46.) A

47.) A

Explanation:

46.) To increase the force with which the wire is pushed when the switch is closed, the current flowing through the wire should be increased and the stronger magnet should be used.

Remember that

F = BIL

The force is directly proportional to magnetic field B and current I

a. I and II only

47.) Since the wires in their coil got hot, and the coil would not turn, this is overheating which may be as a result of to much voltage supply compare to the length of the length of the coil of wire. To correct this, more wire should be added to the coil.

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards