‘Sphere’ শব্দের অর্থ কী?

A

পানি

B

মণ্ডল

C

আকাশ

D

মাটি

‘Sphere’ শব্দের অর্থ কী? Correct Answer

শেয়ার করুন বন্ধুর সাথে

বিসিএস, ব্যাংক, প্রাইমারি সহ সরকারি বেসরকারি চাকুরীর পরীক্ষার প্রস্তুতির জন্য ডাউনলোড করুন Bissoy অ্যাপ

Related MCQ's

A smaller sphere has potential 50V and a larger sphere has potential 100V. How should they be placed so that if they are connected with the help of a wire, the charge will flow from the smaller sphere to the larger sphere? Both the spheres are conducting and hollow.

A

Concentrically

B

Touching each other

C

It is never possible

D

The smaller sphere should be grounded

A metal sphere of surface area 0.0225 m2 is in an evacuated enclosure whose walls are held at a very low temperature. Electric current is passed through resistors embedded in the sphere causing electrical energy to be dissipated at the rate of 75 W. If the sphere surfaces temperature is measured to be 560 K, while in steady state, calculate emissivity of the sphere surface

A

0.498

B

0.598

C

0.698

D

0.798

The ratio of total surface area and volume of a sphere is 1 : 7. This sphere is melted to form small spheres of equal size. The radius of each small sphere is1/6ththe radius of the large sphere. What is the sum (in cm2) of curved surface areas of all small spheres?

A

31276

B

36194

C

25182

D

33264

A sphere of radius 'R₁' is enclosed in a sphere of radius 'R₂'. The view (or shape) factor for radiative heat transfer of the outer sphere with respect to the inner sphere is

A

0

B

$$\frac{{{{\text{R}}_2}}}{{{{\text{R}}_1} + {{\text{R}}_2}}}$$

C

1

D

$${\left( {\frac{{{{\text{R}}_1}}}{{{{\text{R}}_2}}}} \right)^2}$$

A sphere is on H.P and a section plane is perpendicular to both the reference planes is cutting the sphere such that the section divides the sphere to 1⁄4 th and 3⁄4 th part the front view and side view will be ___________

A

circle, line

B

ellipse, circle

C

line, ellipse

D

line, circle

An average convective heat transfer coefficient for flow of air over a sphere has been measured by observing the temperature-time history of a 12 mm diameter copper sphere (density = 9000 kg/m3 and c = 0.4 k J/kg K) exposed to air at 30 degree Celsius. The temperature of the sphere was measured by two thermocouples one located at the center and the other near the surface. The initial temperature of the ball was 75 degree Celsius and it decreased by 10 degree Celsius in 1.2 minutes. Find the heat transfer coefficient

A

27.46 W/m2 K

B

21.76 W/m2 K

C

29.37 W/m2 K

D

25.13 W/m2 K

If the radius of a sphere is tripled, then what will be the ratio of the surface area of original sphere to that of the new sphere?

A

1:9

B

1:3

C

9:1

D

3:1

If the radius of a sphere is made five times, what will be the ratio of the volume of new sphere to the ratio of volume of original sphere?

A

5:1

B

25:1

C

1:625

D

125:1

Two sphere of radius 2 cm each are melted and casted into a single sphere. What would be the radius of this new sphere?

A

4 cm

B

161/3 cm

C

121/3 cm

D

2 cm

Volume of a cube of side ‘$$l$$’ and volume of a sphere of radius ‘r’ are equal. Both the cube and the sphere are solid and of same material. They are being cast. The ratio of the solidification time of the cube to the same of the sphere is

A

$${\left( {\frac{{4\pi }}{6}} \right)^3}{\left( {\frac{{\text{r}}}{l}} \right)^6}$$

B

$$\left( {\frac{{4\pi }}{6}} \right){\left( {\frac{{\text{r}}}{l}} \right)^2}$$

C

$${\left( {\frac{{4\pi }}{6}} \right)^2}{\left( {\frac{{\text{r}}}{l}} \right)^3}$$

D

$${\left( {\frac{{4\pi }}{6}} \right)^2}{\left( {\frac{{\text{r}}}{l}} \right)^4}$$