NDA Physics 2014/2015 Past Questions

When a ball of mass 2kg moving with a velocity of 10 ms^-1 collides head-on with a ball of mass 3 kg, and both moves together after the collision, the common velocity is ___.

If r is the radius of the earth and g is the acceleration at its surface, then the acceleration g1 at an orbit distance R from the centre of the earth is given by

When water in a bucket is whirled fast overhead the water does not fall out at the top of the motion because

An object of mass 4kg moves round a circle of radius 6 m with a constant speed of 12 ms^-1. calculate the angular velocity.

A flat plate is cut in the shape of a square of side 20.0 cm with an equilateral triangle of side 20.0 cm adjacent to the square. Calculate the distance of the centre of mass from the apex of the triangle.

A mercury-in-glass thermometer reads 20° at the ice point and 100° at the steam point. Calculate the Celsius temperature corresponding to 70° on the thermometer.

A brass rod is 2m long at a certain temperature. Calculate the linear expansion of the rod for a temperature change of 100k. (Take the linear expansivity of brass as 1.8 x 10^-5 K^-1

A force of 100 N is needed to lift a load of 50 N using a pulley system whose velocity ratio is 4. The efficiency of the system is __.

A small boy is standing in the corridor of a train that is travelling at 100km/h, he jumps up to the height of about 0.3m when he lands his feet should touch the floor.

A piece of rubber 10 cm long stretches 6 mm when a load of 100 N is hung from it. What is the strain?

The following are derived units except __.

Which of the following statements is true of the vector shown below?

A man walks 10km due south. The displacement of the man from the initial position is __.

An object starts from rest and moves with a uniform acceleration. Which of these quantities varies/vary directly with time?
I. Velocity
II. Displacement
III. Acceleration

A stone is thrown horizontally from the top of a tall building with a velocity of 10 m/s. If the stone falls at a distance of 50 m from the foot of the building, calculate the height of the building

A vehicle of mass m is driven by an engine of power P from rest. Find the minimum time it will take to acquire a speed v.

A box of mass 40kg is being dragged along the floor by a rope inclined at 60° to the horizontal; The frictional force between the box and the floor is 100N and tension of the rope is 300 N, How much work is done in dragging the box the through a distance of 4 m?

Which of the following statement are true about frictional force?
I. It is always a disadvantage
II. It is sometimes a disadvantage
III. It always exists where there is a relative motion of two bodies that are in contact
IV. It is sometimes very useful

The energy contained in a wire when it is extended by 0.02 m by a force of 500 N is __.

A copper cube weighs 0.25 N in air, 0.17 N when completely immersed in paraffin oil and 0.15 N when completely immersed in water. The ratio of up thrust in oil to upthrust in water is

A wheel and axle is used to raise a load of 500 N by the application of an effort of 250 N. If the radii of the wheel and the axle are 0.4 cm and 0.1 cm respectively, the efficiency of the machine is

Which of the following phenomenon can occur only with sound waves?

A whistle is blown and an echo is heard from a distant cliff three seconds later. If the speed of sound in air is 0.33 kms^-1, how far away is the cliff?

If radio waves travel at a speed of 3 x 10⁵ kms^-1; then the wavelength of a radio wave of frequency 1.5 MHz is ___.

Find the wavelength for a radio station broadcast at a frequency of 200 KHz. if the speed of the wave is 3 x 10⁸ m/s.

An opaque object is floating 3.5 cm above the bottom of a liquid but appears to be floating 5.0 cm from the surface. If the liquid is 10.0 cm deep. Its refractive index is __.

Which of the following statements about lenses is true?

An eclipse of the moon occurs when the earth lies in a direct line between the sun and the moon, such an eclipse does not occur every month, however. because

An object is illuminated by an extended source as shown below. The umbra consists of the region between

Snell's Law concerning the passage of light from one medium to another states that

In the periscope shown below, the image will appear at the point

Thermal equilibrium between two objects exists when

An open pipe closed at one end produces its first fundamental note. If the velocity of sound in air is v and L the length of the pipe, the frequency of the note is

Given that Young's modulus for aluminium is 7.0 x 10¹⁰Nm^-2 and density is 2.7 x 10 kgm^-3. Find the speed of the sound produced if a solid bar is struck at one end with a hammer.

A 2000 W electric heater is used to heat a metal object of 5kg initially at 10°C. If a temperature rise of 30°C is obtained after 10 min, the heat capacity of the material is

An electron of charge 1.6 x 10^-19 C is accelerated between two metal plates. If the kinetic energy of the electron is 4.4 x 10^-17J, the potential difference between the plates is

A magnetic field is said to exist at a point if a force is __.

Which of these statements is true of a soft-iron?
I. It retains its magnetism much longer than steel
II. It is more easily magnetized than steel
III. It is more easily demagnetized than steel
IV. It produces a stronger magnet than steel.

Which of the following pairs of light rays shows the widest separation in the spectrum of white light?

The most suitable cell used for short interval switches in electric bells is a __.