**Answer:**

kJ

**Explanation:**

= mass of 1 mole of water = 18 g

= given mass of water = 50 g

Number of moles of water in the given amount is given as

= Heat of fusion of water = 6.01 kJ/mol = 6010 J/mol

= specific heat of water = 75.3 J/mol

= Change in temperature = 22.0 °C

Amount of heat required is given as

J

kJ

**Answer:**

**R = 2481 Ω **

**L= 1.67 H**

**Explanation:**

**(a)** We have an inductor L which has an internal resistance of R. The inductor is connected to a battery with an emf of E = 12.0 V. So this circuit is equivalent to a simple RL circuit. It is given that the current is 4.86 mA at 0.725 ms after the connection is completed and is 6.45 mA after a long time. First we need to find the resistance of the inductor. The current flowing in an RL circuit is given by

i = E/R(1 -e^(-R/L)*t) ** (1)**

at t --> ∞ the current is the maximum, that is,

i_max = E/R

solve for R and substitute to get,

R= E/i_max

**R = 2481 Ω **

**(b)** To find the inductance we will use i(t = 0.940 ms) = 4.86 mA, **solve (1) for L as, **

Rt/L = - In (1 - i/i_max
)

Or,

L = - Rt/In (1 - i/i_max
)

substitute with the givens to get,

L = -(2481 Si) (9.40 x 10-4 s)/ In (1 - 4.86/6.45
)

**L= 1.67 H**

<u><em>**note :**</em></u>

<u><em>**error maybe in calculation but method is correct**</em></u>

**Answer:**

option A: the government paid private industries for goods and services.

**Explanation:**

**Answer:**

**(ii) The Electric Field reports the Electric Force on a 1C test charge placed at a particular location.
**

**(iii) The Electric Potential reports the Electric Potential energy of a 1C test charge place at a particular location.**

** (iv) The spatial derivative of the electric potential at a particular location reports the electric field at that location.**

**ii, iii and iv are true.**

**Explanation:**

Electric force per unit charge is the electric field. It is a vector. E = F/q.

Electric potential is the electric potential energy per unit charge and is a scalar quantity, like the electric potential. V = U/q where U is the electric potential energy and q the charge.

Electric field exists due to a difference of potential, between two different points.E =dV/dx .