Question

SECTION-C
1. Draw the labeled diagram of an electric motor? Explain its principle and working. . What is
the function of a split ring in an electric motor?
2. Three resistances are connected as shown in the fig. A current of 1A flows through a
resistance of 532.
zo
250
Calculate (a) total resistance of circuit
(a) current through remaining two resistors
(b) potential difference between AB.
OR
Three resistors of resistances 1022, 2012, 30 are connected in series first and then in parallel to an
external voltage source of 6V. What would be the current drawn in each case?​

Answer 1

$\huge\underline\bold\red{AnsweR...}$

Question Draw the labeled diagram of an electric motor? Explain its principle and working. . What isthe function of a split ring in an electric motor?

Ans.Electrical energy is converted in into mechanical energy in an electric motor.

Working of electric motor:

As shown in the diagram, when a current is passed through the coil PQRS the coil starts rotating anti clockwise because a downward force acts on length PQ and at the same time an upward force acts on RS. Therefore, the coil rotates in anti clockwise direction. In the length PQ, current flows from P to Q and magnetic field acts from left to right. According to Fleming's left hand rule a downward force acts on the length PQ and an upward force acts on length RS. These two forces causes the coil to rotate anti clockwise.

When coil complete half rotation, the position of PQ and RS interchange, the half ring D comes in contact with brush A and half-rign C comes in contact with brush B, therefore the direction of current in coil PQRS gets reversed. Now the current flows through the coil in the direction SRQP. The direction of the current through the coil PQRS reverse after every half rotation. As a result, the coil rotates in same direction.

☞For diagram of electric motor refer above attachment...

----------------------------------------

Question. Three resistors are connected as shown in the diagram.

Three resistors are connected as shown in the diagram.Through the resistor 5 ohm, a current of 1 ampere is flowing.

Three resistors are connected as shown in the diagram.Through the resistor 5 ohm, a current of 1 ampere is flowing.(i) What is the current through the other two resistors?

Three resistors are connected as shown in the diagram.Through the resistor 5 ohm, a current of 1 ampere is flowing.(i) What is the current through the other two resistors?(ii) What is the p.d. across AB and AC?

Three resistors are connected as shown in the diagram.Through the resistor 5 ohm, a current of 1 ampere is flowing.(i) What is the current through the other two resistors?(ii) What is the p.d. across AB and AC?(iii) What is the total resistance?

Ans. Refer to above attachment....

Explanation:

ₕₒₚₑ ᵢₜ ₘₐy ₕₑₗₚₛ ᵤ...