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. August 2016

NLM: Forces

Q- A 40.0 kg crate is suspended between the floor and the ceiling using two spring scales, one attached to the ceiling and one to the floor. If the lower scale reads 117N, what is the reading of the upper scale? Ignore the Weight of the scales.

Solution:

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Electromagnetic Induction

Q- A loop of wire in the shape of a rectangle of width w and length L and a long, straight wire carrying a current I lie on a tabletop as shown in figure. Suppose the current is changing with time according to I = a + b*t, where a and b are constants. Determine the emf that is induced in the loop if…

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Vectors: Components

Q- In each of these, the x and y components of a vector are given. Find the magnitude and direction of the vector.

(a) x = −4.0 cm, y = +5.0 cm.

(b) Fx = +160 N, Fy = −50.0 N.

Solution:

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Potential Well

Q- The longest wavelength line in the spectrum emitted by an electron trapped in an infinitely deep square well is 610 nm. What is the width of the well?

Solution:

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Newtons Laws of motion: Equilibrium

Q- A 2.0 kg ball tied to a string fixed to the ceiling is pulled to one side by a force F to an angle of 37 degrees from the ceiling.

a) Just before the ball is released and allowed to swing back and forth, how large is the force F that is holding the ball in position.

b) Just before the ball is r…

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Interference of light: Double-slit experiment

Q- Light of wavelengths 480 nm and 620 nm is incident on a double slit of slit width 0.54 mm. How far apart are the second-order fringes for these two wavelengths on a screen 1.6 m away?

Solution:

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Friction

Q- A box sits on a horizontal wooden ramp. The coefficient of static friction between the box and the ramp is 0.43. You grab one end of the ramp and lift it up, keeping the other end of the ramp on the ground. What is the angle between the ramp and the horizontal direction when the box begins to sli…

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L-C Circuit : Resonance

Q- The tuning circuit of an AM radio contains an LC combination. The inductance is 0.200 mH, and the capacitor is variable, so that the circuit can resonate at any frequency between 550 KHz and 1650 KHz. Find the range of values required for C.

Solution:

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Circular Motion

Q- A curve in a road forms part of a horizontal circle. As a car goes around it at a constant speed 14.0 m/s, the total force on the driver has magnitude 130N. What is the total vector force on the driver if the speed is 18.0 m/s instead?

Solution:

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Magnetic Field

Q1- What is the flux density at point P in Figure due only to the 3-A current in the portion of wire 2 shown?

Q2- What is the total flux density at point P

Solution:

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Sliding without Tipping

Q- Determine the horizontal force F necessary to slide the 100 kg crate of height 1.5 m and width 1.00 m. The crate has uniform mass distribution. The coefficient of static friction at the floor is ms = 0.4. What is the maximum height h for which with this force the crate will slide without tipping?

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Electrostatics: Potential

Q- Two charges are fixed in place with a separation d. One charge is positive and has seven times (n = 7) the magnitude of the other charge, which is negative. The positive charge lies to the left of the negative charge. Relative to the negative charge, locate the two spots on the line through the c…

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Falling Under Air Drag

Q- A skydiver of mass 80.0 kg jumps from a slow-moving aircraft and reaches a terminal speed of 50.0 m/s

  1. What is the acceleration of the skydiver when her speed is 30.0 m/s2?  
  2. What is the drag force on the skydiver when her speed is 50.0 m/s?
  3. What is the drag force on the skydiver when her s…

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Happy Independence Day

Wave Optics - Diffraction Grating

Q- White light (λ= 400 – 700 nm) is incident on a 600 line/mm diffraction grating. What is the width of the first order rainbow on the screen 2.0 m behind the grating?

Solution:

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Electromagnetic Induction

Q- An automobile has a vertical radio antenna 1.20 m long. The automobile travels at 72.0 km/h on a horizontal road where the Earth's magnetic field is 50.0 µT directed toward the north and downward at an angle of 60.0° below the horizontal. Calculate the maximum possible magnitude of EMF induced in…

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Stable Equilibrium

Q- A uniform rod of mass M and length l can rotate freely in a vertical plane about a smooth hinge at one end. A light inextensible string attached to the other end of the rod passes over a smooth peg which is at a height h (greater than l) vertically above the hinge and supports a mass m hanging fr…

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Potential Divider

Q- A 20V battery has an internal resistance r = 2 ohms. Design a voltage divider supplying 5V (Open circuit) from the end-points of resistor R2 = 10 ohms. Find the load current when RL = 15 ohms is connected to the R2 of the divider and the voltage under load.

Solution:

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Projectile Motion

Q- An airplane with a speed of 75 m/s is climbing upward at an angle of 37.0 ° with respect to the horizontal. When the plane's altitude is 600 m, the pilot releases a package.

(a) Calculate the distance along the ground, measured from a point directly beneath the point of release, to where the p…

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Electrostatics: Electric Flux

Q- Consider a closed triangular box resting within a horizontal electric field of magnitude E =7.80 X 104 N/C as shown in Figure. Calculate the electric flux through (a) the vertical rectangular surface, (b) the slanted surface, and (c) the entire surface of the box.

Solution:

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