Egyptian scholastic test (EST) Physics October 2021 with answers and explanation provided by Mrs Hadil Fayzi. EST physics real test questions available with explanation exclusively on sat-act-est.com. Only with us you will find EST physics practice exams with answers and explanation online for free.

Answer D

KE = ½ mv^{2}

o.96 = ½ x 3 x v^{2}

v= 0.8 m/s

Answer D

P= fd/t = 1000×300/ 30 = 10000 W

Answer B

As transverse waves particles vibrate perpendicular to the direction of wave’s propagation

Answer c Atoms with the same atomic number but with different atomic masses are called isotopes. Isotopes have identical chemical properties, yet have very different nuclear properties

Answer A

Radioactive decay is the emission of energy in the form of ionizing radiation. The ionizing radiation that is emitted can include alpha particles, beta particles and/or gamma rays.

## EST Physics

Answer D

Q= m L = 500X10^{-3 }X 3.35X10^{5 }= 1.675X10^{5} J

Answer E

Q = mc t

8000 = 0.4 x c x ( 44.4 – 24.4 )

C= 1 j/g ^{0} c

Answer A

= 120 – P

= 120 – 10^{5 }X ( 3.5 – 0.2 ) 10^{-3 }= – 210 J ISOBARIC PROCESS ( 1L = 10^{-3 }m^{3 })

## EST Physics

Answer A

Ruler is used to measure length in cm ,caliper may measure in cm or mm ,micrometer is used to measure small thickness in mm

Answer D

n = sin ϴi/ sin ϴ r

1.5 = sin 30 / sin ϴ r

ϴ r = sin 30/ 1.5 = sin^{-1 }( 1/3 )

Answer A + 2 q which is the total charge is divided equally between the 2 spheres

Answer B

V= 2

1500 = 2 / ( 1-0.4 ) d = 450 m

Answer c

Objects like wool, hair or glass rod tend to give off electrons, and get positively charged. While objects like silk or plastic comb acquire electrons and get negatively charged

## EST Physics

Answer E

F= ma

F= ( 1+ 2 ) a = 3 a a= 1/3 F

Answer A

d = vi + ½ g t^{2 } d is directly proportional with t^{2}

distance between rocks increases while both are falling

Answer D

T = 2 Viy / g = 2 Vi sin ϴ / g = 2×10 sin 30 /10 = 1 sec

Answer B

total internal reflection takes place at the boundary between two transparent media **when a ray of light in a medium of higher index of refraction approaches the other medium at an angle of incidence greater than the critical angle**.

Answer D

R eq = r/2 + 10

R = V/I

r/2+ 10 = 10/0.5

r = 20 ohm

## EST Physics

Answer C

ʎ R / d

1.9 x 10^{– 3 } = ʎ x 0.6 / 0.2 x 10^{-3}

ʎ = 0.63 x 10^{– 6 } micrometer = 0.63 m

Answer c

n2 / n1 = ʎ1/ ʎ 2 = y1/ y 2

1.5 / 1 = 1.9 / y 2 y2 = 1.26 mm

Answer B

d = vi t + ½ at^{2}

200 = 0 + ½ x 5 t^{2}

t = 8.9 s

Answer B

F = n / t = 120 / 60 = 2 v= F X ʎ = 2X 0.2 = 0.4 m/s

Answer E

I = 6Sin 50 πt pure resistance means v,I are in same phase Sin 50 πt = 1

E = Pt = I2 R t = 62 x 4 x 20 = 2880 J

Answer B

t1 = t2

d/15 = 250 – d /-10 t1 = 750/15 = 50 s

t 2 = 250 – 750 / -10 = 60 s

Answer F

d = v delta t = -10 x 10 = -100 I meters

Answer A

Q= 72 C1= 6 C2 = 4 C Total = 10

72/10 = 7.2 for each part

6×7.2 = 43.2 microcoloumb

4×7.2 = 28.8 microcoloumb

## EST Physics

Answer B

V= Q/C = 72/10 = 7.2 volt

Answer D

G = G M /r ^{2 }= 6.67×10^{-11 }x 5.98 x 10^{24 } / ( 6700 x 10^{3 })^{2 } = 8.8 m/s^{2}

Answer B

Focal length = distance between focus and center of curvature =20 cm

Since 2F=40 cm

It is given that object is kept at 60 cm from center of curvature since object is beyond 2F.

Nature of image → Real and inverted

Size of image → Smaller

Position → Between F and 2F on other side of lens.

Answer c

V= ʎ x f

330 = ʎ x 60×10^{3}

ʎ = 0.0055 m = 5.5 mm

Answer c

W x o.4 = ( 350 x0.2 ) + ( 100 x 0.5 )= 300 N

## EST Physics

Answer A

d = Vi t + ½ g t^{2}

14 = ½ x10 t^{2}

t = root 2.8

30 = ½ x 10t2

T = root 6

Answer c

Q LOST = Q GAINED

Mc

0.08 x 4200 x ( 70- t ) = 0.1 x4200 ( t – 28 )

336 ( 70 – t ) = 420 ( t – 28 )

0.8 ( 70 – t ) = t – 28

1.8 t = 56+ 28

t = 84/1.8 = 47 ^{0} c

Answer D

Horizontal component of velocity of aeroplane and horizontal component of velocity of bomb is same

The velocity of the bomb is unaffected by the vertical acceleration

## EST Physics

Answer c

2g h = vf^{2 }– vi^{2}

Vf = root 2 g h

Vf = vi + g t

Root 2gh = gt

T = root 2gh/g = root 2h/g

Answer A

R _{t }= 2+ ( ¼ + 1/6 + 1/10 )^{-1} = 3.9 ohm

I= V/R= 12/3.9 = 3 A V 2 OHM = IR = 3X2 = 6 VOLTS V REST = 6

I = V/R 10 OHM = 6/10 = 0.6 A

Answer B

P= V^{2}/ R

Answer A

As unlike charges attract

Answer E

T= BIAN sides of rectangular coil are parallel to the field

Answer D

it will be halved as they are inversely proportional

Answer A

= 633X10^{-9 }X1/0.2 X 10^{-3 }= 6.33X10^{-3 } m

Answer B

F= MV^{2}/r M = 1000X4X10^{4 }/60^{2} = 11.11 x10^{3} kg

## EST Physics

Answer D

A = v^{2 }/r = 60^{2}/1000 = 3.6 m/s^{2}

Answer A

The equivalent resistance of a group of resistors connected in parallel is less than any one of the resistors

Answer E

The resistance which is short circuited will be eliminated from the circuit so the total resistance decreases and current intensity and voltage increases

R=V/I

Answer D

Circuit consists of a resistance and a inductor coil

Answer c

I= 5-2.5t t=0 I= 5

Emf = L / = 0.5 x5 /2 = 1.25 v

V= IR = 2.5 x0.8 = 2

Answer D

V- emf =2- 1.25 = 0.75

Answer B

## EST Physics online

Answer B

NP/NS = V big / V small 2000/NS = 240/12 NS =100

Answer A

E_{W} = h f _{c} = h c/ʎ

3×1.6×10^{-19 }= 6.6×10^{-34} x3x 10^{8} / ʎ

Answer D

Resonance occurs in a series circuit when the supply frequency causes the voltages across L and C equal and opposite in phase

Answer A

F is inversely proportional with square distance 1/2^{2} = ¼

Answer A

As it’s a scalar quantity having magnitude only

## EST Physics

Answer A

Mechanical energy = pe at the top = mgh = 0.4 x10x2= 8 J

Answer D

When 2 waves slightly different in frequency interfere they form beats

Answer D

m = 500/10 = 50 Kg F= ma = 50 x 2= 100 N

Answer A

B= µ I / 2π d = 4 πx 10^{– 7} x2 /2π x 0.4 = 10^{-6 } T

Answer C

Force is directly proportional with acceleration according to Newton’s second law

Answer B

µ mg = 12 µ = 12/20 =0.6

## EST Physics

Answer C

2 ad = VF^{2} –VI^{2}

2 a x10 = s^{2} – 10^{2} a= -3.75 m/s2

W = F d = ma d= 8×3.75 x 10 = 300 j

Answer B

0=2×100-3000 V

-200 = -3000 V

V= 0.06 m/s

Answer C

V= F X ʎ When changing medium v is directly proportional with wave length

Answer B

M1v1+ m2v2 = (m1+ m2 ) v 12

2v+ 0 = 3 v12 2v= 3v12 v12= 2/3 v

Answer B

The kinetic energy decreases with time

Answer B

P1V1/T1 = P2V2/T2

300 V/( 23+273) = P2 V/( 323+273 )2

P2=1200 Kpa

Answer D

Its velocity is changing direction

Answer C

Speed of light is constant in any reference frame

## EST Physics

Answer B

W= V/r L = I W

W is inversely proportional with I

W1/W2 = I2/I1 20/W2=5/15 W2=60

Answer A

R= VIX T = VI COS ϴ.T

L1/L2=COS π/COS π/6 L2 = root 3/2 L

Answer B

Answer D

V= Xm W cos W t = – 3.5 x10^{-2} x( 2π /π )x5 cos 2π = – 0.47 m/s

Answer B

a = V WCOS WT a = -1.5 m/s^{2}

Answer B

U= ½ K X^{2}

T= 2 π ROOT m/ k

π/5 = 2π root o.5 /k k = 50

u=0 .5 x50 x( 1.5×10^{-2})^{2 }u= 0.0056 = 55 mj

Best of luck Mrs Hadil Fayzi EST physics instructor

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