Recently Active Class Vii X Physics Questions

Mass of an electron is- (a)1/1850gm (b)0.1gm (c)9.1x10-28 (d)None of the above ...

There is an equiconvex lens of focal length of 20 cm.If the lens is cut into two equal parts perpendicular to the principle axis,the focal length of each part will be- (a)20cm (b)10cm (c)40cm (d)15cm ...

The door of a running refrigerator inside a closed room was left open.Then- (a)The room will be cooled slightly (b)The temperature of the room will be lowered (c)The temperature of the room will not be affected (d)The room wi ...

Prove that mechanical energy is conserved when a body is thrown upwards. Please help me! My exam starts in two days and I need this answer by Friday. IT'S EXTREMELY URGENT. ...

The value of gas constant R for hydrogen is- (a)1/2 calorie (b)2 calories/mole Kelvin (c)4 calories (d)1 calorie Please explain how??? ...

In given gas,sound travels at a speed of 300m/s.Find the order of the root-mean-square velocity of the molecules of this gas- (a)40m/s (b)400m/s (c)4000m/s (d)4m/s ...

*Image* What is the net resistance in the circuit? Current flows from the direction of the resistor R1 to the resistor R4. Give suitable reasons with your answer. ...

An ice cube contains an iron ball in it and floats in water contained in a vessel.What will happen if the ice melts away? a. The water level will go up. b. The water level will go down c. There will be no change in the water ...

two masses A and B of 10kg and 5kg respectively are connected with a string passing over a frictionless pulley fixed at the corner of a table as shown. The coefficient of static friction of A with the table is 0.2. The minimu ...

If the force exerted by 2 charges of 2μC and x C separated by a distance of 25 cm equals the force exerted by a current carrying conductor of 9A in a magnetic field of 32 Tesla and of length 50 cm at angle 30. Then find the ...

Find the force exerted when Current is 5, Magnetic Field Strength is 4 and length is 1/2 m. ...

the image is reversed but i hope u can understand... *Image* two masses A and B of 10kg and 5kg respectively are connected with a string passing over a frictionless pulley fixed at the corner of a table as shown. The coeffici ...

*Image* If R1 = 3 ohm R2 = 2 ohm R3 = 7.5 ohm R4 = 5 ohm R5 = 5 ohm R6 = 10 ohm R7 = 20 ohm Find the equivalent resistance between A and B. ...

If voltage is a scalar quantity, how can it be negative? Thanx in advance... ...

Work, energy, potential etc. are all scalar, but they can have negative values too. How can scalar be negative? They should neither be positive nor be negative as they are independent of the direction. P.S.: W=FScosΘ; F=vect ...

If image distance is 20 cm and object distance is 40 cm ,then how much is the radius of the curvature? ...

Can anyone please show the derivation of F = qvBSin(theta)? Please use graphs to explain,and clearly state what is being done in each step to derive the final equation. ...

at sunset, the sun appears higher than its actual position....can u please explain y??? ...

Difference between which two points gives 230 volts as the p.d.? ...

A truck and a car are moving with the same K.E. on a straight line road. If their engines are turned off at the same time, which one of them will stop at a lesser distance? ...

What is optical density exactly???why is it different from the normal density???both are based on the arrangement of molecules in diff. medium....then.... ...

Can you people please name a site where I can learn about the mechanism of different simple gadgets like camera,telescope,radio etc. but with nice illustrations and simple words...please. ...

A concave lens can be converging if it is placed in a liquid of (a) R.I more than its R.I (b)R.I less than its R.I (c)both cases possible (d)never possible ...

A light wave was sent and it returned after 0.00001 secs .Then how much was the distance? ...

why does it appear that the morning sun moves faster than the midday sun? ...

A boy stands in front of a tall wall and claps. The boy continues to clap every time an echo is heard. Another boy finds that the time taken between the firs and 51st clap is 18s. v=? 330m/s 340 m/s 333m/s none ...

Speed of light in air or vacuum is (in cm/s) 3 X10^8 2 X 10^8 2 X 10^5 3 X 10^10 Your Answer d Correct Answer a HOW IT IS POSSIBLE WHEN IT IS IN CM/S? ...

for light to reflect obeying the laws of refection the surface must be smooth rough neither smooth nor rough any surface would do Your Answer d Correct Answer a BOTH IN SMOOTH AND ROUGH SURFACES LAWS OF REFLECTION ARE OBEYED ...

Which of the following is not the characteristic of the image formed by the pinhole camera? real Virtual erect B & D Your Answer c Correct Answer b THE CHARACTERISTICS OF A PINHOLE CAMERA STATES THAT THE IMAGE IS REAL,INVERTE ...

Image formed by a convex mirror is real virtual magnified B & C Your Answer b Correct Answer d Image formed by a convex mirror is always virtual,erect and diminished then why the answer is virtual and magnified?(option d) ...