If a lamp has resistance of 120 W when it operates at 200 W, what is the applied voltage?
a. 120 V
c. 110 V
b. 220 V
d. 155 V
[Ques. 2] A uniform solid sphere rolls down an incline of height 3 m after starting from rest. In order to calculate its speed at the bottom of the incline, one needs to know:
a. the mass of the sphere.
c. the mass and the radius of the sphere.
b. the radius of the sphere.
d. no more than is given in the problem.
[Ques. 3] If a 500-W heater carries a current of 2.00 A, what is the voltage across the ends of the heating element?
a. 2000 V
c. 0.008 V
b. 125 V
d. 250 V
[Ques. 4] An object of radius R and moment of inertia I rolls down an incline of height H after starting from rest. Its total kinetic energy at the bottom of the incline:
a. is gR/I.
b. is I/gH.
c. is 0.5 Ig/H.
d. cannot be found from the given information alone.
[Ques. 5] The unit for rate of energy transformation, the watt, in an electric circuit is equivalent to which of the following?
a. AW
c. V/W
b. V/s
d. VA
[Ques. 6] A meter stick is hinged at its lower end and allowed to fall from a vertical position. If its moment of inertia is ML2/3, with what angular speed does it hit the table?
a. 5.42 rad/s
c. 1.22 rad/s
b. 2.71 rad/s
d. 7.67 rad/s
[Ques. 7] The quantity volt is equivalent to which of the following?
a. J/C
c. JC
b. C/W
d. Jm
[Ques. 8] A hoop (I = MR2) is rolling along the ground at 10 m/s. It comes to a hill and starts going up. Assuming no losses to friction, how far does it travel vertically up the hill before it stops?
a. 10 m
c. 5.1 m
b. 3.7 m
d. 7.7 m
[Ques. 9] A resistor is connected to a battery with negligible internal resistance. If you replace the resistor with one that has quadruple the resistance, by what factor does the power dissipated in the circuit change?
a. 0.25
c. 2.0
b. 4.0
d. 0.50
[Ques. 10] A solid cylinder of mass 3.0 kg and radius 0.2 m starts from rest at the top of a ramp, inclined 15, and rolls to the bottom without slipping. (For a cylinder I = 0.5MR2.) The upper end of the ramp is 1.5 m higher than the lower end. Find the linear speed of the cylinder when it reaches the bottom of the ramp. (g = 9.8 m/s2)
a. 4.7 m/s
c. 4.0 m/s
b. 4.4 m/s
d. 2.4 m/s
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