Get premium membership and access questions with answers, video lessons as well as revision papers.
(i) A soft-iron core reduces losses due to hystesis i.e. the soft iron is easily magnetized and demagnetized.
(ii) A laminated core reduces losses due to eddy currents. The core cuts off the loops of each current reducing them considerably.
johnmulu answered the question on February 20, 2017 at 04:56
- State Lenz’s Law of electromagnetic induction.(Solved)
State Lenz’s Law of electromagnetic induction.
Date posted: February 20, 2017. Answers (1)
- What causes electromagnetic damping in a moving coil galvanometer?(Solved)
What causes electromagnetic damping in a moving coil galvanometer?
Date posted: February 18, 2017. Answers (1)
- State the laws of electromagnetic induction.(Solved)
State the laws of electromagnetic induction.
Date posted: February 18, 2017. Answers (1)
- Radiant heat from the sun penetrates a glass sheet while radiant heat from burning wood is cut off by the glass sheet. Explain(Solved)
Explain the fact that radiant heat from the sun penetrates a glass sheet while radiant heat from burning wood is cut off by the glass sheet.
Date posted: February 18, 2017. Answers (1)
- State the difference between X-rays and gamma rays in the way in which they are produced.(Solved)
State the difference between X-rays and gamma rays in the way in which they are produced.
Date posted: February 18, 2017. Answers (1)
- State the reasons why radio waves signals are easier to receive than TV (television) signals in a place surrounded by hills (Solved)
State the reasons why radio waves signals are easier to receive than TV (television) signals in a place surrounded by hills
Date posted: February 18, 2017. Answers (1)
- State two uses of microwaves.(Solved)
State two uses of microwaves.
Date posted: February 18, 2017. Answers (1)
- Arrange the following in order of increasing frequencies (Solved)
Arrange the following in order of increasing frequencies - Gamma radiation, Radio waves, Infrared, and X - rays
Date posted: February 18, 2017. Answers (1)
- A balloon is filled with a gas which is lighter than air. It is observed to rise in air up to a certain height.(Solved)
A balloon is filled with a gas which is lighter than air. It is observed to rise in air up to a certain height. State a reason why the balloon stops rising.
Date posted: February 18, 2017. Answers (1)
- a)State the condition necessary for a body to float in fluid
b) A ship made of steel is observed to float on water yet the density of steel is approximately eight times that of water(Solved)
a) State the condition necessary for a body to float in fluid
b) A ship made of steel is observed to float on water yet the density of steel is approximately eight times that of water. Explain this observation.
Date posted: February 18, 2017. Answers (1)
- State the law of flotation (Solved)
State the law of flotation
Date posted: February 18, 2017. Answers (1)
- When a piece of metal is placed on water, it sinks. But when the same piece of metal is placed on a block of wood, both are found to float. (Solved)
When a piece of metal is placed on water, it sinks. But when the same piece of metal is placed on a block of wood, both are found to float. Explain this observation.
Date posted: February 18, 2017. Answers (1)
- A block of glass of mass 250 g floats in mercury. What volume of glass lies under the surface of the mercury? (Density of mercury is 13.6 x 103Kgm-3)(Solved)
A block of glass of mass 250 g floats in mercury. What volume of glass lies under the surface of the mercury? (Density of mercury is 13.6 x 103Kgm-3)
Date posted: February 18, 2017. Answers (1)
- A block of wood weighing 2.0 N is held under water by a string attached to the bottom of a container. The tension in the string is 0.5 N(Solved)
A block of wood weighing 2.0 N is held under water by a string attached to the bottom of a container. The tension in the string is 0.5 N. Determine the density of the wood.
Date posted: February 18, 2017. Answers (1)
- Ice cubes float on water and solid benzene sinks in liquid benzene, Explain(Solved)
Explain the following observation: Ice cubes float on water and solid benzene sinks in liquid benzene
Date posted: February 18, 2017. Answers (1)
- A solid copper sphere will sink in water while a hollow copper sphere of the same mass may float.(Solved)
A solid copper sphere will sink in water while a hollow copper sphere of the same mass may float. Explain this observation.
Date posted: February 18, 2017. Answers (1)
- When a bus goes a round bend on a flat road, it experiences a centripetal force, State what provides the centripetal force and the purpose of banking roads at bends. (Solved)
a) When a bus goes a round bend on a flat road, it experiences a centripetal force. State what provides the centripetal force
b) State the purpose of banking roads at bends.
Date posted: February 18, 2017. Answers (1)
- Explain applications of uniform circular motion in daily life. (Solved)
Explain applications of uniform circular motion in daily life.
Date posted: February 18, 2017. Answers (1)
- State two ways in which the centripetal force on a body can be increased.(Solved)
State two ways in which the centripetal force on a body can be increased.
Date posted: February 18, 2017. Answers (1)
- Define the term angular velocity(Solved)
Define the term angular velocity
Date posted: February 18, 2017. Answers (1)