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 = Â½ mv^{2}

o.96 = Â½ 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 waveâ€™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 â€“ 24.4 )

C= 1 j/g ^{0} c

Answer A

= 120 – P

= 120 â€“ 10^{5 }X ( 3.5 â€“ 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 Ï´i/ sin Ï´ r

1.5 = sin 30 / sin Ï´ r

Ï´ 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 + Â½ 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 Ï´ / 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

ÊŽ R / d

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

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

Answer c

n2 / n1 = ÊŽ1/ ÊŽ 2 = y1/ y 2

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

Answer B

d = vi t + Â½ at^{2}

200 = 0 + Â½ x 5 t^{2}

t = 8.9 s

Answer B

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

Answer E

I = 6Sin 50 Ï€t pure resistance means v,I are in same phase Sin 50 Ï€t = 1

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

Answer B

t1 = t2

d/15 = 250 â€“ d /-10 t1 = 750/15 = 50 s

t 2 = 250 â€“ 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 â†’ Real and inverted

Size of image â†’ Smaller

Position â†’ Between F and 2F on other side of lens.

Answer c

V= ÊŽ x f

330 = ÊŽ x 60×10^{3}

ÊŽ = 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 + Â½ g t^{2}

14 = Â½ x10 t^{2}

t = root 2.8

30 = Â½ x 10t2

T = root 6

Answer c

Q LOST = Q GAINED

Mc

0.08 x 4200 x ( 70- t ) = 0.1 x4200 ( t â€“ 28 )

336 ( 70 â€“ t ) = 420 ( t â€“ 28 )

0.8 ( 70 â€“ t ) = t â€“ 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 }â€“ 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+ ( Â¼ + 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/ÊŽ

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

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} = Â¼

Answer A

As itâ€™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= Âµ I / 2Ï€ d = 4 Ï€x 10^{– 7} x2 /2Ï€ x 0.4 = 10^{-6 } T

Answer C

Force is directly proportional with acceleration according to Newtonâ€™s second law

Answer B

Âµ mg = 12 Âµ = 12/20 =0.6

## EST Physics

Answer C

2 ad = VF^{2} â€“VI^{2}

2 a x10 = s^{2} â€“ 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 ÊŽ 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 Ï´.T

L1/L2=COS Ï€/COS Ï€/6 L2 = root 3/2 L

Answer B

Answer D

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

Answer B

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

Answer B

U= Â½ K X^{2}

T= 2 Ï€ ROOT m/ k

Ï€/5 = 2Ï€ root o.5 /k k = 50

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

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