Correct Answer: B. the dielectric between the plates is non-conducting.

Explanation

In a parallel plate capacitor, two conductive plates are separated by a dielectric material (usually an insulator). When a voltage (potential difference) is applied across the plates, it creates an electric field between them, which stores electrical energy in the form of electric potential. The dielectric material between the plates is a non-conducting material, which means it does not allow the flow of electric current. Therefore, in a DC circuit, where current is the flow of charge over time, current cannot flow through the dielectric. Instead, the dielectric serves to store energy in the electric field between the plates without allowing the passage of charge.

Correct Answer: B. crust

Explanation

a. Let the number of sides of polygon Q be x

therefore, No. of sides of polygon P = 2x

then, \(\frac{360}{x} - \frac{360}{2x}\) = 45,

\(\frac{360}{x} - \frac{180}{x}\) = 45

L. C. M = x

360 - 180 = 45x

x = \(\frac{180}{4}\) = 4

therefore, the number of P polygon = 2x = 2 x 4 = 8

b. Area of semi-circle = \(\frac{\pi r^2}{2}\)

but Area of the semi-circle = 32π

\(\frac{\pi r^2}{2}\) = 32π

\(r^2 = 32\times2 = 64\)

\(r^2 = \sqrt{64}\) = 8cm.

Circumference of semi-circle = πr + 2r

= π(8) + 2(8)

= 8π + 16

= 8(π + 2 ) cm

Correct Answer: A. metals have very high melting points

Correct Answer: D. 1111₂

Correct Answer: A. 960\(\Omega\)

Explanation

P = \(\frac{V_2}{R}\) \(\Rightarrow\) R = \(\frac{V_2}{p}\)

= \(\frac{240\times 240}{60}\)

= 960\(\Omega\)

Explanation

(a) Forces of adhesion are forces between molecules of different substances while forcea of cohesion are forces between molecules of the same substance.

(b) Examples: Adhesion — force between water molecules and glass molecules.

Cohesion — force between mercury molecules.

Correct Answer: B. ll, lll, l,lV

Correct Answer: B. 3.14159

Explanation

(a) \(3(3n - 1) + 5(2n + 1) = 135\)

\(9n - 3 + 10n + 5 = 135\)

\(19n + 2 = 135\)

\(19n = 135 - 2 = 133\)

\(n = \frac{133}{19} = 7\)

(b) Radius of a cylinder = 14 cm

side of a cube = 22 cm

\(\therefore \frac{22}{7} \times 14 \times 14 \times h = 22 \times 22 \times 22\)

\(44 \times 14 \times h = 22 \times 22 \times 22\)

\(h = \frac{22 \times 22 \times 22}{44 \times 14}\)

= \(\frac{121}{7} cm\)

TSA of a cylinder = \(2\pi r (r + h) = 2 \times \frac{22}{7} \times 14 (14 + \frac{121}{7})\)

= \(88(\frac{98 + 121}{7}) = \frac{88 \times 219}{7}\)

= \(\frac{19272}{7} cm^{2}\)

TSA of a cube = \(6s^{2}\)

= \(6 \times 22 \times 22\)

= \(2904 cm^{2}\)

Ratio = \(\frac{19272}{7} : 2904\)

= \(73 : 77\)