Loading....

Press & Hold to Drag Around |
|||

Click Here to Close |

**Question 1**
**Report**

A man clapping his hands at regular intervals observes that the echo of a clap coincides with the next clap. If the reflecting cliff is 160m away and the speed of sound is 320ms-1, what is the frequency of the clapping?

**Answer Details**

Total distance = 2 x 160 = 320cm

Total time = 320320 $\frac{320}{320}$ = 1s

F = 11 $\frac{1}{1}$ = 11 $\frac{1}{1}$

= 1Hz

**Question 3**
**Report**

A dentist obtains a linear magnification of 4 of a hole in a tooth by placing a concave mirror at a distance, of 2.0cm from the tooth. The radius of Curvature of the mirror is

**Answer Details**

v = 4u, if u = 2cm, v = 8cm

F = uvu+v $\frac{uv}{u+v}$

= 2×82+8 $\frac{2\times 8}{2+8}$

= 1.6cm

r = 2F

= 2 x 1.6

= 3.2cm

**Question 4**
**Report**

Which of the following represents the correct precision if the length of a piece of wire is measured with a meter rule?

**Answer Details**

**Question 5**
**Report**

A gas occupies a volume of 300cm3at a temperature of 27oC. What is its volume at 54oC, when the pressure is constant?

**Answer Details**

V1T1 $\frac{{V}_{1}}{{T}_{1}}$ = V2T2 $\frac{{V}_{2}}{{T}_{2}}$

30027+273 $\frac{300}{27+273}$ = V254+273 $\frac{{V}_{2}}{54+273}$

V2 = 327cm3

**Question 6**
**Report**

When two objects P and Q are supplied with the same quantity of heat, the temperature change in P is observed to be twice that of Q. The ratio of the specific heat capacity of P to Q is

**Answer Details**

θ $\theta $p = 2θ $\theta $q

mq = 2mp

Cp X mp X θ $\theta $p = Cq x mq x θ $\theta $q

CpmqθqCqmpθq $\frac{{C}_{p}{m}_{q}\theta q}{{C}_{q}{m}_{p}\theta q}$ = θq×2mp2θqmp $\frac{\theta q\times 2mp}{2\theta qmp}$

CpCq $\frac{{C}_{p}}{Cq}$ = 22

**Question 7**
**Report**

A pencil is placed vertically between a concave mirror and its focal point. The image of the pencil in the mirror will be

**Answer Details**

**Question 8**
**Report**

A uniform meter rule QR is balanced on a knife edge which is 55cm from R, when a mass of 10g is hung at P as shown above, the mass of the meter rule is (Note that QP is 10cm)

**Answer Details**

**Question 9**
**Report**

Which of the following assumptions is made in a simple pendulum experiment? the

**Answer Details**

**Question 11**
**Report**

In an experiment in which molten naphthalene is allowed to cool, the cooling curve in fig 5 was obtained, the temperature 80∘C
${80}^{\circ}C$ is known as

**Answer Details**

**Question 12**
**Report**

In which of the following arrangements is the wavelength in an increasing order?

**Answer Details**

**Question 13**
**Report**

A constant force of magnitude F acts on an object of mass 0.04kg initially at rest at a point O. if the speed of the object when it has moved 50m from O is 500ms-1, what is the value of F?

**Answer Details**

F = ma and V2 = U2 + 2aX

F = m(V2−U2)2X $\frac{({V}^{2}-{U}^{2})}{2X}$

= 0.04(5002−02)2×50 $\frac{({500}^{2}-{0}^{2})}{2\times 50}$

F = 100N

**Question 14**
**Report**

Which of the following is most strongly deflected by magnetic field?

**Answer Details**

**Question 15**
**Report**

In fig 6, a ray of light in air strikes a glass plate at an angle of incidence 60 degrees, the reflected ray is observed to be perpendicular to the refracted ray, what is the refractive index of the glass

**Answer Details**

**Question 16**
**Report**

A ball is thrown vertically into the air with an initial velocity u. What is the greatest height reached?

**Answer Details**

Using V2 = U2 - 2gS

V = 0ms-1 at greatest height

S = u22g

**Question 17**
**Report**

A 1000kg elevator is descending vertically with an acceleration of 1.0ms-2, if the acceleration due to gravity is 10ms-2, the tension in the suspending cable is

**Answer Details**

The elevator is descending so the weight acts in line with the acceleration which is downwards. So according to Newton's law,

mg(weight) -R (tension/reaction) = ma

**Question 21**
**Report**

Fig 4 represents a block-and-tackle pulley system on which an effort of W newtons supports a load of 120.0N if the efficiency of the system is 40% then the value of W is

**Answer Details**

**Question 23**
**Report**

In fig 3, three forces F1, F2, and F3 acting at O are in equilibrium. If the magnitude of F1 is 10N,and the magnitude of F2 is 5N, find the magnitude of F3

**Answer Details**

**Question 24**
**Report**

Two objects, one having three times the mass of the other, are dropped at the same time from a tall building. When they are above the ground, the two objects will have the same

**Answer Details**

**Question 25**
**Report**

When a box of mass 45kg, is given an initial speed of 5ms-1 it slides along a horizontal floor a distance of 3m before coming to a rest. what is the coefficient of kinetic friction between the box and the floor? (G = 10ms-2)

**Answer Details**

**Question 26**
**Report**

The sign of the change on a charged glass rod may be determined with

**Answer Details**

**Question 27**
**Report**

If the fig above E is an accumulator with negligible internal resistance. and the EMF 9.0V, The the total current is

**Answer Details**

**Question 29**
**Report**

What is the effect of the increase in the size of the hole of a pin-hole camera on the image? it

**Question 31**
**Report**

A wave of frequency 10Hz forms a stationary wave pattern in a medium where the velocity is 20cms-1. The distance between adjacent nodes is

**Answer Details**

λ $\lambda $ = vf $\frac{v}{f}$

= 2010 $\frac{20}{10}$

= 2cm ; distance between adjacent nodes

**Question 32**
**Report**

The mode of heat transfer which does not require a material medium is

**Answer Details**

**Question 33**
**Report**

Which of the following properties makes metals ideal for cooking utensils?

**Answer Details**

**Question 34**
**Report**

The specific latent heat of fusion of lead is the amount of heat required to

**Answer Details**

**Question 36**
**Report**

If the refractive index of glass is 1.5, what is the critical angle at the air-glass interface?

**Answer Details**

sin ic 1n $\frac{1}{n}$ = 11?5 $\frac{1}{1?5}$

i = sin-111?5 $\frac{1}{1?5}$

= sin-11015 $\frac{10}{15}$

= sin-123

**Question 37**
**Report**

A lens of focal length 12.0cm forms an upright image three times the size of a real object. The distance between the object and the images is

**Answer Details**

F = 12cm, V = 3u

F = uvu+v $\frac{uv}{u+v}$

12 = u×3uu+3v $\frac{u\times 3u}{u+3v}$

u = 16cm, and v = 48cm

therefore, distance between u and v

v = 48 - 16 = 32cm

**Question 38**
**Report**

Which of the following is a derived unit?

**Answer Details**

Force is a derived quantity, it's unit is a derived unit

**Question 39**
**Report**

A heavy object is suspended from a string and lowered into water so that it is completely submerged. The object appears lighter because

**Answer Details**

**Question 41**
**Report**

Fig 1 is a graph of force against extension for a spiral spring, the force constant of the spring is given by the

**Answer Details**

**Question 43**
**Report**

A rectangular tank contains water to a depth of 2m, if the base is 4m x 3m, calculate the force on the base (Density of water = 103kgm-3, g = 10ms-2)

**Answer Details**

Volume = 2 x 4 x 3 = 24m3

mass = V x D = 24 x 103

F = mg

= 24 x 103 x 10

= 24 x 104

**Question 45**
**Report**

The angle between the magnetic meridian and the geographic meridian at a locality on the earth is the

**Answer Details**

**Question 46**
**Report**

The wavelength of ultraviolet radiation is 400nm. If the speed of light in air is 3 x 108ms-1, then the frequency of the ultraviolet radiation is

**Answer Details**

F = Vλ $\frac{V}{\lambda}$

= 3×108400×109 $\frac{3\times {10}^{8}}{400\times {10}^{9}}$

= 75 x 1015Hz

Would you like to proceed with this action?