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. May 2016

Magnetic Force

Q- A horizontal wire of length 0.10m and mass 0.020kg carries a current in the earth’s magnetic field where it is horizontal and of magnitude 5.0*10-5 T.                            

a) Determine the minimum magnitude of the current in the wire if the wire remains moti…

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Interference (sound)

Q- Your friend Ram wants to talk to you. You both are 12 meters apart. A long wall is located 8 meters to the side of both. When Ram talks, you hears the sound coming directly from Ram, and the sound that reflects off the wall. What is the lowest frequency that Ram should talk so that when the two w…

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EMF

(On request – Nicol)

Q- A dry cell (battery) does 7.12 J of work through chemical energy to transfer 5.92 C of charge between the terminals of the cell. What is the electric potential difference between the two terminals? 

Solution:

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Conical Pendulum

Q- A small bob of mass m is suspended by a string of length l. the bob is moving in a horizontal circle, with constant speed, such that the string makes an angle θ with the vertical. Find:

a) Speed of the bob

b) Angular momentum and

c) work done to bring it to rest.

Solution:

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Transformers

(On request – Colin)

Q- A step-down transformer has an output of 14.5 V and 0.66 A when connected to an incoming 268 V line. What is the ratio of primary to secondary loops? 
a) What current does the transformer draw from the incoming line? 
b) What is the power output of the transformer?

Solu…

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Waves

Q- Two waves traveling in same direction are present at a point in space have amplitudes d1(t)=4sin(wt) and d2(t)=4cos(wt). Determine the resultant amplitude at that point.

Solution:

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Reflection of Light

Q- A person stands 4.0 meters in front of a floor-to-celing mirror. Her eyes are 1.9 meters above the floor. She sees the reflection of light from her shiny toe of shoe.
a) At what angle of incident must the light from the toe of her shoe strike the mirror so the light will reach her eyes?
b) How hi…

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Specific Heat Capacity

Q1- A 100Kg player runs at 8.0 m/s when he slides on one knee over the try line to score a try. Assume that friction between the knee and the grass surface converts 40% of the player’s original kinetic energy to heat in the skin tissue of the knee ( tissue mass is approximately 15g) and determine th…

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NLM

Q- A rubber band of spring constant K is wrapped (without tension) around a metal rod of diameter D. The rod is then accelerated upward with an acceleration 100g. What will be the gap between the metal rod and the rubber band at the bottom now? Mass per unit length of the rubber band is m.

Solution…

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Optical Fiber

(On request- Pradeep)

Q- Find the maximum angle of incidence θ1 of a ray on the plane surface that would propagate through an optical fiber that has a core index of refraction of 1.499, a core radius of 44.00 µm, and a cladding index 1.496.

Solution:

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Motion in 1D - Variable acceleration

Q- At t=0, car A starts from rest at point 1. It moves towards the right with an acceleration of 0.4t m/s2. At the same time car B starts from point 2, 200 m ahead of A, with a constant acceleration of 2 m/s2 to the right. Find:

a) Speed of car A at the end of 200 m section.

b) Time to travel of s…

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Refraction: Prism

Q- A triangular glass prism with apex angle 60 degree has refractive index 1.50. Find:

a) The angle of incident on the first surface so that the light will pass symmetrically through the prism.

b) The angle of deviation for this symmetric refraction.

c) The angle of deviation if the angle of inci…

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Motion in 1D - Variable Force

Q- A snowmobile weighing 1000 lbs starts from rest, coasts down a 50 incline. If the force of friction opposing the motion is 40 lbs and the air resistance in pounds is numerically equal to 1.5 times the speed in feet per second, find:

a) An expression of the acceleration

b) An expression for the …

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Current Electricity- Power

(On request -Te'Shia)

Q- A 12 V battery holds 100 J of energy. It discharges all of this energy at a steady rate over the course of 2 hours while powering a flashlight. How much power did the battery deliver to the flashlight? What was the current?

Solution:

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Reflection

Q- (On request- Arvind)

Solution:

Simple Harmonic Motion

Q- A block-spring system oscillates with amplitude of 3.50 cm. The spring constant is 250 N/m and the mass of the block is 0.600 kg.

(a) Determine the mechanical energy of the system.

(b) Determine the maximum speed of the block.

(c) Determine the maximum acceleration.

Solution:

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Electromagnetic Induction.

Q- An aluminum ring of radius r1 and resistance R is placed around the top of a long air-core solenoid with n turns per meter and smaller radius r2 as shown in Figure. Assume that the axial component of the field produced by the solenoid over the area of the end of the solenoid is one-half as strong…

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Motion in 1D

Q- A rocket rises vertically from rest, with an acceleration of 3.2 m/s2 until it runs out of fuel at an altitude of 1200 m. After this point, its acceleration is that due to gravity:

(a) What is the velocity of the rocket when it runs out of fuel

(b) How long does it take it to reach this point

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AC

Q- A series AC circuit contains the following components: R = 150 Ohm, L = 250 mH, C = 2.00 micro-Farad and a source with Vmax = 210 V operating at 50.0 Hz. Calculate the

a) Inductive reactance

b) Capacitive reactance

c) Impedance

d) Maximum current

e) Phase angle between  source voltage and cu…

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Simple Harmonic Motion

Q1- A particle moves in simple harmonic motion with a frequency of 1.80 Hz and and amplitude of 6.00 cm. What is it maximum speed of the particle?

Q2- A transverse wave on a string is described by the following wave function.

y = (0.115 m) sin (3.14*x/8 + 12.56*t)

(a) Determine the transverse spe…

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