67486 + Interview Questions in Secondary School in Physics

1.	Iron has a density of 7900kg m-³.what is the volume of 2kg of iron
Answer» $\huge \underline{ \rm \red{hello}}$ Question:- Iron has a density of 7900KG m-³.what is the volume of 2KG of iron. _________________________________ Given :- Density of Iron = 7900kg m-³ To FIND :- The volume of 2kg of iron Solution:- Mass of iron=2kg Density of iron=7900 kg/m-³ Density = mass × volume → 7900 = 2 × volume $\sf\underline{ \rm \red{volume}} = \frac{7900}{2} \\ \\ \sf\underline{ \rm \red{volume}} \: = 3950 {m}^{3}$

1.

Iron has a density of 7900kg m-³.what is the volume of 2kg of iron

Answer»

$\huge \underline{ \rm \red{hello}}$

Question:-

Iron has a density of 7900KG m-³.what is the volume of 2KG of iron.

_________________________________

Given :-

Density of Iron = 7900kg m-³

To FIND :-

The volume of 2kg of iron

Solution:-

Mass of iron=2kg

Density of iron=7900 kg/m-³

Density = mass × volume

→ 7900 = 2 × volume

$\sf\underline{ \rm \red{volume}} = \frac{7900}{2} \\ \\ \sf\underline{ \rm \red{volume}} \: = 3950 {m}^{3}$

Discussion

2.	The value of g at centre and pole of the earth is??
Answer» The VALUE of G at EQUATOR is about 9.78 m/s² and 9.83 m/s² at poles Mark as BRAINLIEST if this HELPED you!

2.

The value of g at centre and pole of the earth is??

Answer»

The VALUE of G at EQUATOR is about 9.78 m/s² and 9.83 m/s² at poles

Mark as BRAINLIEST if this HELPED you!

Discussion

3.	A 130 m long train is moving in up direction with speed72 km/h. Another train of 120 m long is moving in downdirection with speed of 108 km/h. The time in which secondtrain crosses the first train will be
Answer» Explanation: RELATIVE speed is 180 km/h which is EQUAL to 180 * 5/18 m/s i.e. 50 m/s the distance to be covered is equal to 250m. therefore TIME taken = 250/50 s = 5 s

3.

A 130 m long train is moving in up direction with speed72 km/h. Another train of 120 m long is moving in downdirection with speed of 108 km/h. The time in which secondtrain crosses the first train will be

Answer»

Explanation:

RELATIVE speed is 180 km/h which is EQUAL to 180 * 5/18 m/s

i.e. 50 m/s

the distance to be covered is equal to 250m. therefore TIME taken = 250/50 s

= 5 s

Discussion

4.	Three forces of 10N,4N and 3N act on a body in directions north, south and east respectively. Find the magnitude and direction of the resultant force
Answer» Answer: The direction of the RESULTANT force is EAST and the MAGNITUDE is 6N Explanation:

4.

Three forces of 10N,4N and 3N act on a body in directions north, south and east respectively. Find the magnitude and direction of the resultant force

Answer»

Answer:

The direction of the RESULTANT force is EAST and the MAGNITUDE is 6N

Explanation:

Discussion

5.	Two bodies have masses in the ratio 5 : 1 andkinetic energies in the ratio 125 : 9. Calculate theratio of their velocities.
Answer» Answer: Ratio of the MASS of the BODY = 5 : 1` Ratio of the Kinetic Energy of the body = 125/9 Since, K.E. = 1/2 mv² Therefore, Ratio of K.E.₁ : K.E.₂ = m₁v₁²/m₂v₂² ∴ v₁²/v₂² = K.E.₁/K.E.₂ × m₂/m₁ ∴ v₁²/v₂² = 125/9 × 1/5 ∴ v₁²/v₂² = 25/9 ∴ v₁/v₂ = 5/3 Hence, the ratio of the VELOCITY of the body a to the velocity of the body b is 5 : 3. Hope it HELPS.

5.

Two bodies have masses in the ratio 5 : 1 andkinetic energies in the ratio 125 : 9. Calculate theratio of their velocities.

Answer»

Answer:

Ratio of the MASS of the BODY = 5 : 1`

Ratio of the Kinetic Energy of the body = 125/9

Since, K.E. = 1/2 mv²

Therefore, Ratio of K.E.₁ : K.E.₂ = m₁v₁²/m₂v₂²

∴ v₁²/v₂² = K.E.₁/K.E.₂ × m₂/m₁

∴ v₁²/v₂² = 125/9 × 1/5

∴ v₁²/v₂² = 25/9

∴ v₁/v₂ = 5/3

Hence, the ratio of the VELOCITY of the body a to the velocity of the body b is 5 : 3.

Hope it HELPS.

Discussion

6.	Describe how an FET can be used as voltage variable resistor
Answer» ANSWER: MARK as brainliest and folow me plz Explanation: FET is a DEVICE that is USUALLY operated in the constant-current PORTION of its output characteristics. But if it is operated on the region prior to pinch-off (that is where VDS is small, say below 100 mV), it will behave as a voltage-variable resistor (WE).

6.

Describe how an FET can be used as voltage variable resistor

Answer»

ANSWER: MARK as brainliest and folow me plz

Explanation: FET is a DEVICE that is USUALLY operated in the constant-current PORTION of its output characteristics. But if it is operated on the region prior to pinch-off (that is where VDS is small, say below 100 mV), it will behave as a voltage-variable resistor (WE).

Discussion

7.	A car is moving on a straight road covers one third of the distance with a speed of 20 km/h and the resa speed of 60 km/h. The average speed of the car is(1) 40 km/h(2) 50 km/h(3) 36 km/h(4) 55 km/h
Answer» Answer: Given: ⅓rd distance travelled by 20 km/hr and the rest distance travelled by 60 km/hr To find: Average speed of the BODY Concept: Average speed is DEFINED as the RATIO of Total distance to the total time taken. Since distance is involved , average speed can never be ZERO, it's ALWAYS positive. Calculation: Let the total distance travelled be s , Then distance travelled with 20 km/hr is s/3 , the rest 2s/3 is travelled with 60 km/hr. $v \: avg. = \dfrac{total \: distance}{total \: time}$ $= > v \: avg. = \dfrac{s}{( \dfrac{ \frac{s}{3} }{20}) + (\dfrac{ \frac{2s}{3} }{60}) }$ $= > v \: avg. = \dfrac{1}{ \dfrac{1}{60} + \dfrac{1}{90} }$ $= > v \: avg. = \dfrac{1}{ \dfrac{(3 + 2)}{180} }$ $= > v \: avg. = \dfrac{180}{5}$ $= > v \: avg. = 36 \: km \: {hr}^{ - 1}$ So final answer : $\boxed{ \red{ \large{ \sf{ \bold{ v \: avg. = 36 \: km \: {hr}^{ - 1}}}}}}$

7.

A car is moving on a straight road covers one third of the distance with a speed of 20 km/h and the resa speed of 60 km/h. The average speed of the car is(1) 40 km/h(2) 50 km/h(3) 36 km/h(4) 55 km/h

Answer»

Answer:

Given:

⅓rd distance travelled by 20 km/hr and the rest distance travelled by 60 km/hr

To find:

Average speed of the BODY

Concept:

Average speed is DEFINED as the RATIO of Total distance to the total time taken.

Since distance is involved , average speed can never be ZERO, it's ALWAYS positive.

Calculation:

Let the total distance travelled be s , Then distance travelled with 20 km/hr is s/3 , the rest 2s/3 is travelled with

60 km/hr.

$v \: avg. = \dfrac{total \: distance}{total \: time}$

$= > v \: avg. = \dfrac{s}{( \dfrac{ \frac{s}{3} }{20}) + (\dfrac{ \frac{2s}{3} }{60}) }$

$= > v \: avg. = \dfrac{1}{ \dfrac{1}{60} + \dfrac{1}{90} }$

$= > v \: avg. = \dfrac{1}{ \dfrac{(3 + 2)}{180} }$

$= > v \: avg. = \dfrac{180}{5}$

$= > v \: avg. = 36 \: km \: {hr}^{ - 1}$

So final answer :

$\boxed{ \red{ \large{ \sf{ \bold{ v \: avg. = 36 \: km \: {hr}^{ - 1}}}}}}$

Discussion

8.	5. Calculate the height through which a body of mass0.5 kg is lifted if the energy spent in doing so is 1.0 J.Take g = 10 m s2.
Answer» ANSWER: Mass = 0.5 KG Energy = 1 J Gravitational POTENTIAL energy = mgh 1 = 0.5 × 10 × h 1 = 5h Height, h = 0.2 m

8.

5. Calculate the height through which a body of mass0.5 kg is lifted if the energy spent in doing so is 1.0 J.Take g = 10 m s2.

Answer»

ANSWER:

Mass = 0.5 KG

Energy = 1 J

Gravitational POTENTIAL energy = mgh 1 = 0.5 × 10 × h 1 = 5h

Height, h = 0.2 m

Discussion

9.	The resistance of a conducting wire x of length 1m is 5 ohm calculate the resistance of the wire made by the same material whose length is 4 times and area of cross section is 5 times that of wire x (at same temperature)
Answer» Answer: 4 OHM Explanation: EQUATING both the SIDES and found out the RESISTANCE.

9.

The resistance of a conducting wire x of length 1m is 5 ohm calculate the resistance of the wire made by the same material whose length is 4 times and area of cross section is 5 times that of wire x (at same temperature)

Answer»

Answer:

4 OHM

Explanation:

EQUATING both the SIDES and found out the RESISTANCE.

Discussion

10.	A man is standing between two vertical walls 680m apart. He claps his hands and hears two distinct echoes after 0.9 seconds and 1.1 second respectively. What is the speed of sound in air?
Answer» ANSWER: 340M is SPEED of SOUND in AIR

10.

A man is standing between two vertical walls 680m apart. He claps his hands and hears two distinct echoes after 0.9 seconds and 1.1 second respectively. What is the speed of sound in air?

Answer»

ANSWER: 340M is SPEED of SOUND in AIR

Discussion

11.	Write a short note ph change as the cause of tooth decay?
Answer» ANSWER: when the PH of tooth is less than 5.6 than it BEGIN to decay

11.

Write a short note ph change as the cause of tooth decay?

Answer»

ANSWER:

when the PH of tooth is less than 5.6 than it BEGIN to decay

Discussion

12.	Abhay wants to focus sunrays on the piece of paper then which type of mirror he use
Answer» Answer: Abhay should USE concave mirror Explanation: So when the rays of Sun are directed towards the focus, the light falls on very SMALL point on the paper. The paper burns out. Concave mirror CALLED CONVERGING lens which CONVERGE high intensive ray come from infinity cause more heat on a unit surface called focus result the burning of paper .

12.

Abhay wants to focus sunrays on the piece of paper then which type of mirror he use

Answer»

Answer: Abhay should USE concave mirror

Explanation: So when the rays of Sun are directed towards the focus, the light falls on very SMALL point on the paper. The paper burns out. Concave mirror CALLED CONVERGING lens which CONVERGE high intensive ray come from infinity cause more heat on a unit surface called focus result the burning of paper .

Discussion

13.	How the effect of friction was minimised in the experiment of newton's second law of motion
Answer» Explanation: A major source of error in pendulum clocks is thermal expansion; the pendulum rod changes in LENGTH slightly with changes in temperature, causing changes in the RATE of the CLOCK. An increase in temperature causes the rod to expand, MAKING the pendulum longer, so its PERIOD increases and the clock loses time. .

13.

How the effect of friction was minimised in the experiment of newton's second law of motion

Answer»

Explanation:

A major source of error in pendulum clocks is thermal expansion; the pendulum rod changes in LENGTH slightly with changes in temperature, causing changes in the RATE of the CLOCK. An increase in temperature causes the rod to expand, MAKING the pendulum longer, so its PERIOD increases and the clock loses time.

.

Discussion

14.	N x sinC =(a) zero(b) infinity(c)1(d) none of these
Answer» ANSWER: *Here* D *OPTION* is *CORRECT*

14.

N x sinC =(a) zero(b) infinity(c)1(d) none of these

Answer»

ANSWER:

Here D OPTION is CORRECT

Discussion

15.	Hat is the difference between a thermal power plant and a hydro power plant ?(b) Which of the two causes serious air pollutioncauses serious air pollution and how ?
Answer» Answer: Difference between Thermal Power and HYDEL Power. The thermal power is produced by burning coal, petroleum or natural gas in thermal generator. But Hydro-electricity or hydel power is DERIVED from the FORCE of running water by means of dynamo driven by hydro-turbine The burning of fossil fuels Sulfur dioxide emitted from the combustion of fossil fuels like coal, petroleum and other factory COMBUSTIBLES are one the major cause of air pollution. ... But, their overuse is killing our environment as dangerous gases are polluting the environment. Various Causes of Air pollution The burning of fossil fuels. Sulfur dioxide emitted from the combustion of fossil fuels like coal, petroleum and other factory combustibles are one the major cause of air pollution. ... Agricultural activities. ... Exhaust from factories and industries. ... MINING operations. ... Indoor air pollution.

15.

Hat is the difference between a thermal power plant and a hydro power plant ?(b) Which of the two causes serious air pollutioncauses serious air pollution and how ?

Answer»

Answer:

Difference between Thermal Power and HYDEL Power. The thermal power is produced by burning coal, petroleum or natural gas in thermal generator. But Hydro-electricity or hydel power is DERIVED from the FORCE of running water by means of dynamo driven by hydro-turbine

The burning of fossil fuels

Sulfur dioxide emitted from the combustion of fossil fuels like coal, petroleum and other factory COMBUSTIBLES are one the major cause of air pollution. ... But, their overuse is killing our environment as dangerous gases are polluting the environment.

Various Causes of Air pollution

The burning of fossil fuels. Sulfur dioxide emitted from the combustion of fossil fuels like coal, petroleum and other factory combustibles are one the major cause of air pollution. ...
Agricultural activities. ...
Exhaust from factories and industries. ...
MINING operations. ...
Indoor air pollution.

Discussion

16.	गुरुत्वीय त्वरण (g) एवं गुरुत्वाकर्षण नियतांक (G) मेंg= को सत्यापित करो।
Answer» Answer: F = G Mm/ R² F = MG Explanation: mg = G Mm / R² g = G M / R²

16.

गुरुत्वीय त्वरण (g) एवं गुरुत्वाकर्षण नियतांक (G) मेंg= को सत्यापित करो।

Answer»

Answer:

F = G Mm/ R²

F = MG

Explanation:

mg = G Mm / R²

g = G M / R²

Discussion

17.	B-6.Two coherent light sources each of wavelength lambda are separated by a distance 3 lambda. The total no.minima formed on line AB which runs from -infinity to + infinity is:(A) 2(B) 4(C) 6(D) 8
Answer» ANSWER: answer is 8 of the QUESTIONS

17.

B-6.Two coherent light sources each of wavelength lambda are separated by a distance 3 lambda. The total no.minima formed on line AB which runs from -infinity to + infinity is:(A) 2(B) 4(C) 6(D) 8

Answer»

ANSWER:

answer is 8 of the QUESTIONS

Discussion

18.	A 50grams bullet is fired from a 2kg pistol with a speed of 1500mls. what is the speed of recoil of the pistol?
Answer» $\huge{\fbox{\fbox{\bigstar{\mathfrak{\orange{Answer}}}}}}$ M1 V1 = M2 v2 50×1500 = 2000×v2 v2 = 37.5 m/s $\huge{\underline{\bf\green{ ThankS}}}$

18.

A 50grams bullet is fired from a 2kg pistol with a speed of 1500mls. what is the speed of recoil of the pistol?

Answer»

$\huge{\fbox{\fbox{\bigstar{\mathfrak{\orange{Answer}}}}}}$

M1 V1 = M2 v2

50×1500 = 2000×v2

v2 = 37.5 m/s

$\huge{\underline{\bf\green{ ThankS}}}$

Discussion

19.	A charge +q is revolving around a stationary charge +Q of radius r if force b/w carge is F then work done of this motion will be?
Answer» Answer: Given: +q CHARGE is revolving around a charge +Q in a radius "r". Force between the charge is F To find: Work done by the revolving charge in this kind of motion. Concept: Work done by any force is given as the DOT product of Force and DISPLACEMENT. Mathematically, $\boxed{ \sf{ \large{work = \vec F. \: \vec r}}}$ $\sf{ \implies \: work = f \times r \times \cos( \theta)}$ Now in a CIRCULAR motion , the force vector and the displacement vector is at 90° with ANOTHER with one another. We know that cos (90°) = 0 $\sf{ \implies \: work = f \times r \times \cos( 90 \degree)}$ $\sf{ \implies \: work = f \times r \times ( 0)}$ $\sf{ \implies \: work = 0 \: joules}$ So , no work is done .

19.

A charge +q is revolving around a stationary charge +Q of radius r if force b/w carge is F then work done of this motion will be?

Answer»