CIE Physics Paper-1: Specimen Questions 86 - 88 of 109

Question number: 86

MCQ▾

Question

Find the amount of sample left after 18 hours if the half-life is 8 hours and has 0.37 g of the substance.

Choices

Choice (4) Response
a.

0.12 g

b.

0.03 g

c.

7.68 g

d.

1.76 g

Answer

d.

Explanation

Here from given data

τ=8hr

Elapsedtime(t)=18hr

Finalamount(mf)=0.37gm

Formula of half-life is given as,

mf=mi(12)tτ

0.37=mi(12)188

mi=1.76gm

Question number: 87

MCQ▾

Question

The diagram shows a speed-time graph for a body moving with constant acceleration. What is the shaded area under the graph?

Graph of Speed versus Time

Graph of Speed versus Time

In figure graph of speed versus Time for body moving with constant acceleration

Choices

Choice (4) Response
a.

acceleration

b.

distance

c. speed
d.

time

Answer

b.

Explanation

Here in above figure the graph of speed vs time is given.

Then area under the graph denoted speed ⨯ time.

As we know that speed means velocity

Velocity=DistanceTime

Distance=Velocity×Time

Then in this graph area under the graph is distance.

Question number: 88

MCQ▾

Question

What leads to refraction when light travels from air to glass?

Choices

Choice (4) Response
a.

The color of the light changes.

b.

The frequency of the light waves changes.

c.

The speed of the light changes.

d.

The amplitude of the light waves changes.

Answer

c.

Explanation

The process in which light pass through one medium to another medium is known reflection. Here light travels from air to glass. So light travels from rarer medium to denser medium therefore there is change in refracting medium. And because of it the speed of light will changes.

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