Answer: 18 MN/C
Explanation: Taking into account the weigth (m* g) and electric force for a charge in a electric fiel as (q*E) both are equals
so 0.0142 Kg*9.8 m/s^2= q*E
thus E= (0.0142*9.8)/(7.7*10^-9)
Answer:
W = 725 J
Explanation:
given,
mass of wagon = 20 kg
distance of pull = 40 m
angle made with the horizontal = 25°
tension force on the wagon = 20 N
Work done = ?
Horizontal component of the force will help in movement of the wagon.
Horizontal component of force=
F_x = F cos θ
Work done is equal to force into displacement
W = F.s
W = F cos θ.s
W = 20 cos 25° x 40
W = 725 J
hence, work done on pulling the wagon is equal to W = 725 J
Answer:
4Q
Explanation:
Case 1 :
= mass of the metal
= specific heat of the metal
= Change in temperature = 7 - 4 = 3 C
Amount of heat required for the above change of temperature is given as

Case 2 :
= mass of the metal
= specific heat of the metal
= Change in temperature = 19 - 7 = 12 C
Amount of heat required for the above change of temperature is given as

Hence the correct choice is
4Q
Answer:
The internal resistance of the cell is 0.051 ohm.
Explanation:
Given;
emf of the battery, E = 12 V
terminal voltage of the cell, V = 8.2 V
current in the circuit, I = 75 A
let the potential drop of the cell due to internal resistance (r) = Ir
The internal resistance of the cell is calculated from the equation below;
E = V + Ir
where;
r is the internal resistance of the cell

Therefore, the internal resistance of the cell is 0.051 ohm.