MCQ in Physics Part 16 | ECE Board Exam

This is the Multiples Choice Questions Part 15 of the Series in Physics as one of the General Engineering and Applied Sciences (GEAS) topic. In Preparation for the ECE Board Exam make sure to expose yourself and familiarize in each and every questions compiled here taken from various sources including past Board Questions in General Engineering and Applied Sciences (GEAS), Physics Books, Journals and other Physics References.

Continue Practice Exam Test Questions Part 16 of the Series

⇐ MCQ in Physics Part 15 | ECE Board Exam

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751. The weight of a mass of 10 kg at a location where the acceleration of gravity is 9.77 m/s² is

A. 79.7 N

B. 77.9 N

C. 97.7 N

D. 977 N

752. How much does a 30 lbm weigh on the moon? Gravitational acceleration in the moon is 5.47 ft/s² and in earth is 32.2 ft/s².

A. 2.0 lbf

B. 3.2 lbf

C. 3.4 lbf

D. 5.096 lb

753. The mass of air in a room 3 m x 5 m x 20 m is known to be 350 kg. Find its density.

A. 1.167

B. 1.176

C. 1.617

D. 1.716

754. An iron block weighs 5 N and has a volume of 200 cubic centimeters. What is the density of the block?

A. 988 kg/m³

B. 1255 kg/m³

C. 2550 kg/m³

D. 800 kg/m³

755. 100 g of water is mixed to 150 g of alcohol (ρ = 790 kg/m³). Calculate the specific volume of the solution, assuming that it is mixed completely.

A. 0.82 cm³/g

B. 0.88 cm³/g

C. 0.63 cm³/g

D. 1.20 cm³/g

756. 100 g of water is mixed to 150 g of alcohol (ρ = 790 kg/m³). Calculate the specific gravity of the total mixture.

A. 1.862

B. 0.963

C. 0.286

D. 0.862

757. The specific gravity of mercury relative to water is 13.55. What is the specific weight of mercury? The specific weight of water is 62.4 lbf/ft³.

A. 102.3 kN/m³

B. 132.9 kN/m³

C. 150.9 kN/m³

D. 82.2 kN/m³

758. A 16 gram mass is moving at 30 cm/sec while a 4 gram mass is moving in an opposite direction at 50 cm/sec. They collide head on and stick together. Their velocity after collision is

A. 0.14 m/s

B. 0.21 m/s

C. 0.07 m/s

D. 0.28 m/s

759. A 60 ton rail car moving at 1 mile/hr is instantaneously coupled to a stationary 40 ton rail car. What is the speed of the coupled cars?

A. 0.88 mph

B. 1 mph

C. 0.6 mph

D. 0.4 mph

760. A 10 g block slides with a velocity of 20 cm/s on a smooth level surface and makes a collision with a 30 g block moving in the opposite direction with a velocity of 10 cm/s. If the collision is perfectly elastic, what is the velocity of the 30 g block after the collision?

A. 15 cm/s

B. 10 cm/s

C. 25 cm/s

D. 5 cm/s

761. A 60 ton rail car moving at 1 mile/hr is coupled to a second stationary rail car. If the velocity of the two cars after coupling is 1ft/s (in the original direction of motion) and the coupling is completed in 0.5 second, what is the average impulsive force on the 60 ton rail car?

A. 50 lbf

B. 3500 lbf

C. 1200 lbf

D. 60 lbf

762. What momentum does a 40 lbm projectile possess if the projectile is moving at 420 mph?

A. 24,640 lbf-sec

B. 16,860 lbf-sec

C. 765 lbf-sec

D. 523.6 lbf-sec

763. A 10-kg block is raised vertically 3 meters. What is the change in potential energy? Answer in SI units closest to:

A. 320 J

B. 350 kg-m²/s²

C. 294 J

D. 350 N-m

764. An aircraft engine develops a forward thrust of 15,000 N. If the gross mass of the aircraft is 100 tons, what horsepower does the engine develop if it is flying at 1000 kph?

A. 150,000

B. 5585

C. 5400

D. 3108

765. If a 10 kg piece of copper falls 100 m, how much heat might be produced?

A. 3.81 kCal

B. 32 BTU

C. 2300 Cal

D. 9.41 kJ

766. A rocket is moving through a vacuum. It changes its velocity from 9020 ft/sec to 5100 ft/sec in 48 seconds. How much power is required to accomplish this if the rocket’s mass is 13,000 slugs?

A. 1.63 x 10⁷ hp

B. 3.16 x 10⁷ hp

C. 3.61 x 10⁷ hp

D. 1.36 x 10⁷ hp

767. A force of 200 lbf acts on a block at an angle of 28° with respect to the horizontal. The block is pushed 2 feet horizontally. What is the work done by this force?

A. 320 J

B. 480 J

C. 540 J

D. 215 J

768. What average force is necessary to stop a .45 caliber bullet of mass of 15 grams and speed of 300 m/s as it penetrates a block to a distance of 5 cm?

A. 12.5 kN

B. 13.0 kN

C. 13.5 kN

D. 12.0 kN

769. What is the water pressure if manometer is 0.6 m Hg? Mercury is 13.6 times heavier than water.

A. 27.4 kPa

B. 47.2 kPa

C. 79.97 kPa

D. 72.4 kPa

770. A mercury barometer at the base of Mt. Makiling reads 654 mm and at the same time another barometer at the top of the mountain reads 480 mm. Assuming specific weight of air to be constant at 12 N/m³, what is the approximate height of Mt. Makiling?

A. 1,934.5 m

B. 3,508.4 m

C. 4, 168.2 m

D. 2,674.7 m

771. Assuming the barometer reads 760 mm Hg, what is the absolute pressure for 900 mm Hg gauge?

A. 74.213 kPa

B. 221.24 kPa

C. 48 kPa

D. 358 kPa

772. A barometer reads 760 mm Hg and a pressure gage attached to a tank reads 850 cm of oil (sp.gr. 0.80). What is the absolute pressure in the tank in kPa?

A. 168.1 kPa

B. 186.1 kPa

C. 118.6 kPa

D. 161.8 kPa

773. A sealed tank contains oxygen at 27°C at a pressure of 2 atm. If the temperature increases to 100°C, what will be the pressure inside the tank?

A. 4.92 atm

B. 4.29 atm

C. 2.49 atm

D. 9.24 atm

774. A volume of 400 cc of air is measured at a pressure of 740 mm Hg abs and a temperature of 18°C. What will be the volume at 760 mm Hg and 0°C?

A. 376 cc

B. 326 cc

C. 356 cc

D. 366 cc

775. The pressure of the nitrogen gas thermometer is 76 cm at 0°C. What is the temperature of a liquid in which the bulb of the thermometer is immersed when the pressure is seen to be 87.7 cm?

A. 34°C

B. 45°C

C. 60°C

D. 90°C

776. A transportation company specializes in the shipment of pressurized gaseous materials. An order is received for 100 liters of a particular gas at STP (32°F and 1 atm). What minimum volume tank is necessary to transport the gas at 80°F and a maximum pressure of 8 atm?

A. 16 liters

B. 14 liters

C. 10 liters

D. 12 liters

777. A 20 liter sample of gas exerts a pressure of 1 atm at 25°C. If t is expanded into a 40 liter vessel that is held at 100°C, what will be its final pressure?

A. 0.50 atm

B. 1.0 atm

C. 0.315 atm

D. 0.63 atm

778. A 10 lbm object is acted upon by a 4.4 lbf force. What acceleration in ft/s² does the object possess?

A. 12.4

B. 10.1

C. 14.2

D. 13.0

779. A 50 kN truck traveling with a speed of 50 kph hits a lamp post and is brought to rest in 0.1 s. What is the average force of the truck?

A. -408 kN

B. -508 kN

C. -608 kN

D. -708 kN

780. A tennis ball moving horizontally to the left at 40 m/s hits a racket and rebounds horizontally to the right at 30 m/s. If the mass of the ball is 100 grams, find the impulse of the force (in kg-m/s) exerted on the ball by the racket.]

A. 1

B. -1

C. 7

D. 12

781. Two steel balls of masses 500 kg and 50 kg, respectively are placed with their centers 0.5 m apart. The two balls attract with a force of

A. 6.67 x 10^-10 N

B. 6.67 x 10^-7 N

C. 6.67 x 10^-8 N

D. 6.67 x 10^-3 N

782. A 50 g mass hangs at the end of the spring. When 20 grams more are added to the end of the spring, it stretches 7 cm more. Fine the spring constant.

A. 2.8

B. 2.9

C. 4.3

D. 2.5

783. Determine the submerged depth of a cube of steel 0.3 m on each side floating in mercury. The specific gravities of steel and mercury are 7.8 and 13.6 respectively.

A. 0.155 m

B. 0.165 m

C. 0.134 m

D. 0.172 m

784. A block of wood floats in water with 5 cm projecting above the water surface. When placed in glycerine of specific gravity of 1.35, the block projects 7.5 cm above the liquid. Determine its specific gravity.

A. 0.514

B. 0.704

C. 0.836

D. 0.658

785. A solid cube material is 0.75 cm on each side. If it floats in oil of density 800 kg/m³ with one-third of the block out of the oil, what is the density of the material of the cube?

A. 533 kg/m³

B. 523 kg/m³

C. 513 kg/m³

D. 543 kg/m³

786. A hollow cylinder 1 m in diameter and 2 m high weighs 2825 N. How many kN of lead weighing 110 kN/m³ must be fastened to the outside bottom of the cylinder to make it float with 1.5 m submerged in water?

A. 8.5 kN

B. 6.5 kN

C. 1.5 kN

D. 9.5 kN

787. How long must a current of 5 amperes pass through a 10-ohm resistor until a charge of 1200 coulombs passes through?

A. 3 min

B. 1 min

C. 4 min

D. 2 min

788. What is the power required to transfer 97,000 coulombs of charge through a potential rise of 50 volts in one hour?

A. 0.5 kW

B. 1.3 kW

C. 0.9 kW

D. 2.8 kW

789. How much oil at 200°C must be added to 5 grams of the same oil at 20°C to heat it to 70°C?

A. 12.39 grams

B. 29.12 grams

C. 19.23 grams

D. 23.91 grams

790. The temperatures of three different liquids are maintained at 15°C, 20°C and 25 °C respectively. When equal masses of the first two liquids are mixed, the final temperature is 18°C and when equal masses of the last two are mixed, the final temperature is 24°C. What temperature will be achieved by mixing equal masses of the first and last liquid?

A. 15.87°C

B. 10.30°C

C. 8.65°C

D. 23.57°C

791. Three forces, 20 N, 30 N, and 40 N are in equilibrium. Find the largest angle(in degrees) they make with each other.

A. 104.48

B.105.58

C. 106.69

D. 107.96

792. Two forces of 20 units and 30 units act at right angle. What is the magnitude of the resultant force?

A. 36

B. 42

C. 40

D. 44

793. What is the magnitude of the resultant force of the two forces 200 N at 20 degrees and 400 N at 144 degrees?

A. 332.5N

B. 323.5N

C. 313.5N

D. 233.5N

794. A load of 100 lb. is hung from the middle of the rope, which is stretched between two rigid walls 30 ft. apart. Due to the load, the rope sags 4 feet in the middle. Determine the tension in the rope.

A. 165 lbs.

B. 173 lbs.

C. 194 lbs.

D. 149 lbs.

795. A boat moving at 12 kph is crossing a river 500 m wide in which a current is flowing at 4 kph. In what direction should the boat head if it is to reach a point on the other of the river directly opposite in starting point?

A. 19.47 degrees downstream

B. 19.47 degrees upstream

C. 18.43 degrees downstream

D. 18.43 degrees upstream

796. A 100 kg weight rest on a 30 degrees incline plane. Neglecting friction, how much pull must one exert to bring the weight up the plane?

A. 88.67 kg.

B. 100 kg

C. 70.71 kg

D. 50 kg

797. A block weighing 500 kN rest on a ramp inclined at 25 degrees with the horizontal. The force tending to move the block down the ramp is ________.

A. 121 kN

B. 265 kN

C. 211 kN

D. 450 kN

798. A 200 kg crate impends to slide down a ramp inclined at an angle of 19.29 degrees with the horizontal. What is the frictional resistance?

A. 612.38 N

B. 628.38 N

C. 648.16 N

D. 654.12 N

799. A man can exert a maximum pull of 1000 N but wishes to lift a new stone door for his cave weighing 20,000 N. If he uses a lever, how much closer must the fulcrum be to the stone then to his hand?

A. 10 times nearer

B. 20 times farther

C. 10 times farther

D. 20 times nearer

800. A beam rests on a fulcrum, 1.2 m from one end. A weight of 350 kg is suspended from this end causing the beam to balance. If the weight of 350 kg is suspended on the opposite end of the beam, it is necessary to suspend a 1000 kg weight on the first end in order to effect an even balance. Find the length of the beam.

A. 2.48 m

B. 3.24 m

C. 3.43 m

D. 4.21 m

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