Physics — 1993

Which of the following is not an example of a force?

A body moves along a circular path with uniform angular speed of 0.6 rad s -1 and at a constant speed of 3.0ms -1 . Calculate the acceleration of the body towards the centre of the circle.

Which of the following is a derived unit?

A body timed 20 oscillations of a certain pendulum three times and obtained 44.3s, 45.5s and 45.7s respectively. Calculate the mean period of oscillation of the pendulum

A body of mass M1 moving with a velocity U collides with a stationary body of mass M2 and both move with a common velocity V lf linear momentum is conserved, which of the following expressions correctly represents V?

A body of mass m = 0.5 kg is suspended by a string and pulled by a horizontal force of 12N as shown in the diagram. Calculate the tension T in the String if the body is in equilibrium. [Take g as 10ms\(^{-1}\)]

A particle starts from rest and moves with a constant acceleration of 0.5 ms -2 ? Calculate the time taken by the particle to cover a distance of 25m.

A block of material of volume 2 X 10\(^{-5}\)m\(^3\) and density 2.5 x 10\(^3\) kgm\(^{-3}\) is suspended from a spring balance with half volume of the block immersed in water. What is the reading of the spring balance? (Density of water =1.0x10\(^3\) kg m\(^{-3}\) g = 10 ms\(^{-2}\)).

An object is projected with a velocity of 100 ms\(^{-1}\) from the ground level at an angle \(\theta\) to the vertical. If the total time of flight of the projectile is 10 s, calculate θ. (g = 10 ms\(^{-2}\)).

How far will a body move in 4 seconds if uniformly accelerated from rest at the rate of 2 ms-2?

If the temperature of water is gradually increased from 0 o to 4 o C, the density of the water within this range

The expansion of solids can be considered a disadvantage in the

A solid metal cube of side 10 cm is heated from 10 o C to 60 o C. lf the linear expansivity of the metal is 1.2 x 10 5 K -1 , calculate the increase in its volume.

A gas has a volume of 546 cm3 at OºC. What is the volume of the gas at -100ºC if its pressure remains constant?

Which of the following are correct of plane- polarized light? I. Plane polarization of light is the formation of hydrogen bubbles on the particles of light. II. Plane polarization of light is the splitting of light into its spectral components III. Plane-polarized light vibrates in one plane only. IV. Polarization is characteristic of transverse waves.

Longitudinal waves cannot be

An image which cannot be formed on a screen is said to be

The images formed by a diverging lens are always

In the normal use of a simple microscope, a person sees an

A lens of focal length 15.0 cm forms an upright image four times the size of an object. Calculate the distance of the image from the lens

An object is placed between two mirrors which are inclined at an angle of 120° and facing each other. Determine the number of images observed in the two mirrors

In a ripple tank experiment, a vibrating plate is used to generate ripples in the water. If the distance between two successive troughs is 3.5 cm and the wave travels a distance of 31.5 cm in 1.5 s, calculate the frequency of the vibrator

Which of the following have the longest wavelengths?

A man stands in front of a tall wall and produces a sound. If he receives the echo of the sound two seconds later, calculate his distance from the wall. (The speed of sound in air is 330ms -1 )

Which of the following is correct about light and sound waves?

The quality of a note produced by a vibrating string is determined by the

Which of the following is a percussion instrument?

A short chain is usually attached to the back of a petrol tanker and trailing behind it so that the

Which of the following indicates the correct sequence of steps taken in charging a gold-leaf electroscope by induction? l. Removing the ebonite rod ll. Bringing a negatively charged ebonite rod close to the cap III. Earthing the cap IV. Disconnecting the earthing

Which of the following instruments can be used to compare the relative magnitude of similar charges on two given bodies?

The unit of inductance is

A household refrigerator consumes electrical energy at the rate of 200 W. lf electricity costs 5 k per kWh, calculate the cost of operating the appliance for 30 days.

Calculate the escape velocity of a satellite launched from the earth’s surface (Take g as 10ms -2 and the radius of the earth as 6.4 x 10 6 m)

What is the gravitational potential due to a point mass m at a distance from it? (G = gravitational constant)

In a series R - C circuit, the resistance of the resistor is 4 Ω and capacitive reactance is 3 Ω. Calculate the impedance of the circuit

The vector diagram shown below represents the resistance R, the capacitive reactance Xc, the inductive reactance Xc and the impedance, Z in an R-L-C circuit. The current in the circuit will be maximum when

In a purely resistive a.c. circuit, the current I = I o sin wt and voltage, V = V o sin wt. Calculate the instantaneous power dissipated in the circuit in time t.

A point charge of 1.0 x 10 -7 C experiences force of 0.01 N in a uniform electric field. Calculate the magnitude of the strength of the field

The potential difference between two points A and B situated at a distance d apart is V. Which of the following expresses the magnitude of the electric field intensity between the two points assuming the field is uniform?

Which of the following have the greatest penetrating power?

A particle of charge 5C moves perpendicularly to a magnetic Held of magnitude C.01 T. If the velocity of the charge is 1.5ms'2, calculate the magnitude of the force exerted on the particle

The function of the magnanese (IV) oxide in a leclanche cell is to

In the diagram above, three identical lamps each of 100 W are connected in parallel across a potential difference of 250 V. Calculate the reading of the ammeter.

Electrical resistance is the property of an electrical conductor that causes electrical energy to be converted into

Calculate the current, I in the diagram shown above. (Neglect the internal resistance of the cell)

Which of the following is not a conductor of electricity?

ln the diagram below, the galvanometer indicates a null-deflection. What is the potential difference between P and Q?

When a potential difference, V is applied across the ends of a resistor of resistance, R a Current, l passes through the resistor. The heat generated in the resistor in time, t is given by the expression

Electric motor primarily converts

What amount of current would pass through a 10 Ω coil if it takes 21s for the coil to just melt a lump of ice of mass 10g at 0oC if there are no heat losses? (Latent heat of fusion of ice = 336 Jg\(^{-1}\)).

How long does it take a 750 W heater operating at full rating to raise the temperature of 1 kg of water from 40 o C to 70 o C? (Take the specific heat capacity of water as 4200 J kg -1 K -1 and neglect heat losses).

24 Na → 24 mg 4 + X + energy 11 2 The equation above represents a nuclear decay of sodium isotope. What is X?

lf Einstein’s photoelectric equation is represented by hf - W = Φ where h is Planck’s constant, f the frequency of incident radiation and W the work function of the material, what does the symbol Φ up stand for?

The phenomenon of radioactivity was first discovered by

A radioactive substance has a half-life of 20 hours. What fraction of the original radioactive nuclide will remain after 80 hours?

Which of the following is used a nuclear reactor to slow down fast moving neutrons?

According to the kinetic theory of gases the collision of the molecules of a gas with the wall of the container is mainly responsible for the l. temperature of the gas ll. viscosity of the gas Ill. pressure of the gas Which of the statements above is/are correct?

Eight or - particles and size B - particles are emitted from an atom of 92 238 U before it achieves stability. What is the nucleon number of the final product in the chain reaction?

When an atom is in the ground state, it is said to be

Which of the following are emitted from a radioactive substance without altering either the nucleon number or the proton number of the substance?