KU 2018 MCQs

Question 1

Highest penetrating power is of

Accepted Answer

γ-ray

Answer

Α-ray

Answer

Β-ray

Answer

X-ray

Question 2

Which elementary particle is a lepton?

Accepted Answer

Electron

Answer

Neutron

Answer

Proton

Answer

Quark

Question 3

Potential energy source for inducing nuclear fusion reaction is

Accepted Answer

Laser

Answer

X-ray

Answer

Ultraviolet

Answer

Microwave

Question 4

When dipole is rotated by 180° from stable equilibrium, the work done will be:

Accepted Answer

2MB

Answer

MB

Answer

√2 MB

Answer

MB/√2

Question 5

A thin rod of length f/3 is placed along the optical axis of a concave mirror of focal length f such that its image which is real and elongated just touches the rod. The length of the image is

Accepted Answer

f/2

Answer

F

Answer

3f/4

Answer

2f/3

Question 6

Far sightedness is corrected by using

Accepted Answer

Convex lens

Answer

Concave lens

Answer

Bifocal lens

Answer

Cylindrical lens

Question 7

A body moves such that u = at, the distance travelled by it in first 4 second is:

Accepted Answer

8a

Answer

4a

Answer

2a

Answer

12a

Question 8

Which region of the electromagnetic spectrum includes waves with a frequency of 10^7 7 MHz?

Accepted Answer

Radio waves

Answer

Ultraviolet waves

Answer

Infra-red waves

Answer

X-rays

Question 9

The opposite corners of a square contain equal charge Q and other opposite corners contain charge q. The net force on Q is zero if:

Accepted Answer

Q=−2√2 q

Answer

Q=−2q

Answer

Q=+2q

Answer

Q=2√2 q

Question 10

The time period of a satellite orbiting in circular orbit around the Earth is independent of:

Accepted Answer

The mass of the satellite

Answer

Both mass of satellite and radius of its orbit

Answer

Radius of its orbit

Answer

Neither the mass of the satellite nor the radius of its orbit.

Question 11

A cylinder piece of a soft, electrically conducting material has resistance R. It is rolled out so that its length is doubled but its volume stays constant. What is its new resistance?

Accepted Answer

4R

Answer

R/2

Answer

2R

Answer

R

Question 12

A nucleus containing Z protons and N neutrons has mass M. If the mass of the proton is mp and that of neutron is mp , then the mass defect of the nucleus is:

Accepted Answer

Zm_p+Nm_n−M

Answer

M−Zm_p−Nm_n

Answer

M−Zm_p+Nm_n

Answer

Zm_p+Nm_n+M

Question 13

The velocity of sound is generally greater in solids than in gases because:

Accepted Answer

Elasticity of solids is very high

Answer

The density of solid is high but the elasticity is low

Answer

Both the density and elasticity of solids are low

Answer

The density of solid is low but the elasticity is high

Question 14

In one dimension elastic collision, when heavy mass collides with a lighter mass initially at rest,

Accepted Answer

Velocity of heavy mass visible remains same and lighter mass moves in opposite direction with velocity approximately twice of heavy mass

Answer

Both of them stick together and move with same velocity

Answer

Heavy mass comes to rest and lighter mass moves with velocity of heavy mass

Answer

Nothing can be said about velocity of lighter mass

Question 15

Radius of $n^{\text{th}}$ orbit is related to quantum number $n$ as

Accepted Answer

$n^2$

Answer

$\frac{1}{n}$

Answer

$n$

Answer

$\frac{1}{n^2}$

Question 16

An object is placed at a distance u from a simple microscope of focal length f. The angular magnification depends

Accepted Answer

Of f as well as u

Answer

On f but not on u

Answer

On u but on f

Answer

Neither on f nor u

Question 17

The magnification of a telescope in normal adjustment is

Accepted Answer

$\frac{f_o}{f_e}$

Answer

$f_o \times f_e$

Answer

$2f_o \times f_e$

Answer

$f_o + f_e$

Question 18

Unit of coefficient of viscosity is

Accepted Answer

$\frac{\mathrm{N}}{\mathrm{m}^2\,\mathrm{s}^{-1}}$

Answer

$\mathrm{N}\,\mathrm{m}^2\,\mathrm{s}^{-1}$

Answer

$\frac{\mathrm{N}\,\mathrm{m}^2}{\mathrm{s}}$

Answer

$\frac{\mathrm{N}\,\mathrm{m}^2}{\mathrm{s}^2}$

Question 19

At 30°C room temperature, the body takes 4 min to cool from 59°C to 61°C, then how much times does it take to cool from 49°C to 51°C?

Accepted Answer

4 min

Answer

6 min

Answer

5 min

Answer

8 min

Question 20

Ratio of the rms velocity of $\mathrm{H}_2$ molecule to the He atom at the same temperature is

Accepted Answer

$\sqrt{2}:1$

Answer

$2:1$

Answer

$\frac{1}{\sqrt{2}}$

Answer

$1:2$

Question 21

The ratio of centripetal force of two bodies having same mass moving with same velocity in radius of $r_1$ and $r_2$ is

Accepted Answer

$\frac{r_2}{r_1}$

Answer

$\sqrt{\frac{r_2}{r_1}}$

Answer

$\sqrt{\frac{r_1}{r_2}}$

Answer

$\frac{r_1}{r_2}$

Question 22

A cylindrical block of wood has cross-sectional area $A$ and weight $W$. It is totally immersed in water with its axis vertical. The block experiences pressures $p_t$ and $p_b$ at its top and bottom surfaces respectively. Which expression is equal to the upthrust on the block?

Accepted Answer

$(p_b-p_t)A$

Answer

$p_b-p_t$

Answer

$(p_b-p_t)A-W$

Answer

$(p_b-p_t)A+W$

Question 23

The maximum wavelength that can be set in a stretched string of length 'l' is

Accepted Answer

2l

Answer

l/2

Answer

4l

Answer

l/4

Question 24

On doubling the frequency of R-C circuit, impedance

Accepted Answer

Increases

Answer

Decreases

Answer

Remains same

Answer

Doubles

Question 25

A charged particle is in the electric field between two horizontal metal plates connected to a battery, as shown. There is a force F on the particle due to the electric field. The separation of the plates is doubled. What is the new force on the particle?

Accepted Answer

F/2

Answer

F/4

Answer

F

Answer

2F

Question 26

For diffraction to occur

Accepted Answer

The width of the object should be comparable to the wavelength

Answer

The width of the object should be lesser than the wavelength

Answer

The width of the object should be greater than the wavelength

Answer

The width of the object should be half of the wavelength

Question 27

A current of 'I' flows in an electric circuit having a cell of emf E and internal resistance 'r'. The terminal p.d. across the end of cell is:

Accepted Answer

E-Ir

Answer

E+Ir

Answer

E+IR

Answer

Zero

Question 28

Galvanometer is converted to ammeter

Accepted Answer

When a small resistance is connected in parallel

Answer

When a small resistance is connected in series

Answer

When a large resistance is connected in series

Answer

When a large resistance is connected in parallel

Question 29

If uncertainty in position of a particle is equal to de-Broglie wavelength λ, the uncertainty in momentum of the particle is

Accepted Answer

hλ

Answer

2h3λ

Answer

2hλ

Answer

3h2λ

Question 30

What will reduce the systematic errors when taking a measurement?

Accepted Answer

Adjusting the needle on a voltmeter so that it reads zero when there is no potential difference across it

Answer

Timing 20 oscillations, rather than a single oscillations, when finding the period of a pendulum

Answer

Measuring the diameter of a wire at different points and taking the average

Answer

Reducing the parallax effects by using a marker and a mirror when measuring the amplitude of oscillation of a pendulum

Question 31

An organic compound containing oxygen on oxidation gives only carboxylic acid, with change of molecular mass by 14 units. The organic compound is

Accepted Answer

Primary alcohol

Answer

Secondary alcohol

Answer

Aldehyde

Answer

Ketone

Question 32

Reaction between CuO and HNO3 gives

Accepted Answer

Cu(NO3)2+H2O

Answer

CuNO3+H2O

Answer

Cu(NO3)2+H2

Answer

CuNO3+H2

Question 33

Intermediate formed in Friedel Craft's alkylation of benzene is

Accepted Answer

CH3+

Answer

CH3-

Answer

Cl-

Answer

C6H5+

Question 34

How many mole atoms are there in one mole of Ca3(PO4)2?

Accepted Answer

13

Answer

5

Answer

8

Answer

1

Question 35

The bonding in magnesium oxide MgO, is

Accepted Answer

Ionic only

Answer

Ionic and covalent

Answer

Metallic and ionic

Answer

Metallic and covalent

Question 36

The correct sequence of reactions to be performed to convert benzene into m-bromoaniline is

Accepted Answer

Nitration, Bromination, Reduction

Answer

Bromination, Nitration, Reduction

Answer

Nitration, Reduction, Bromination

Answer

Reduciton, Nitration, Bromination

Question 37

The chemical properties of an element are determined by its

Accepted Answer

Electronic structure

Answer

Number of protons plus neutrons

Answer

Number of neutrons

Answer

Number of protons

Question 38

Going across the Periodic table from sodium to aluminium,

Accepted Answer

The melting temperature increases

Answer

The radius of atom increases

Answer

The radius of the metal ion increases

Answer

The bonding in the element changes from metallic to covalent

Question 39

When ammonium nitrate crystals dissolve in water, the entropy of the system

Accepted Answer

Rises, because the ions are arranged more randomly in the solution than in the crystal

Answer

Remains the same

Answer

Falls, because the hydrated ions are more ordered than the solid

Answer

Rises, because the ions in the crystal become hydrated in the solution

Question 40

The hydrocarbon which can react with sodium in liquid ammonia is

Accepted Answer

CH_3 CH_3 C≡CH

Answer

CH_3 CH_2 C≡CCH_2 CH_3

Answer

CH_3 CH_2 CH_2 C≡CCH_2 CH_2 CH_3

Answer

CH_3 CHCHCH_3

27KU 2018

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