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Q1.(a) Calculate the effective resistance across AB. (2 Marks) SOLUTION: SOLUTION: Q1.(b) A magnet kept at the centre of 2 coils A and B is moved to and fro as shown in the figure. The 2 galvanometers show deflection. State with reason whether: x > y or x < y [X and y are magnitudes of deflection] (2 Marks) SOLUTION: X < Y because coil B has more number of turns. Q2. (a) (i) Write one advantage of connecting electrical appliances in parallel combination. (ii) What characteristics should a fuse wire have? (iii) Which wire in a power circuit is connected to the metallic body of the appliance.( 3 Marks ) SOLUTION: https://school.gradeup.co/write-the-advantages-ofconnecting-electrical-appliances-in-i-1nlfag SOLUTION: Q3. (b) the diagram below shows a dual control switch circuit connected to a bulb. (i) Copy the diagram and complete it so that the bulb is switched on. (ii) Out of A and B which one is live wire and which one is neutral wire.( 3 Marks ) SOLUTION: Q4.(i) A fuse is rated 8A. Can it be used with an electrical appliance rated 5KW 200 V? Give a reason. (ii) Name two safety devices which are connected to the live wire of a household electric circuit. (3 Marks) (b) (i) Find the equivalent resistance between A and B. (ii) State whether the resistivity of a wire changes with change in thickness of the wire. (3 Marks) SOLUTION: AKMIC Q5. An electric iron is rated 220V, 2 KW. (i) If the iron is used for 2 hour daily find the cost of running it for one week if it costs Rs 4.25 per KWH. (ii) Why is the fuse absolutely necessary in a power circuit. (4 Marks) SOLUTION: Q6.The diagram shows a coil wound around a U shaped soft iron bar AB. (i) What is the polarity induced at the points A and B when the switch is pressed. (ii) Suggest one way to strengthen the magnetic field in the electromagnet. (iii) What will be the polarities at A and B if the direction of current is reversed in the circuit.(4 Marks) SOLUTION: Q6.(a) (i) Name the colour code of the wire which is connected to the metallic body of an appliance. (ii) Draw the diagram of a dual control switch when the appliance is switched ON.(3 Marks) (b) (i) Which part of particles are responsible for current in conductors? (ii) To which wire of a cable in a power circuit should the metal case of a geyser be connected? (iii) To which wire should the fuse be connected ? (3 Marks) SOLUTION: (a) (i) Green and yellow stripes SOLUTION: Q7.(a) A music system draws a current of 400mA when connected to a 12V battery. (i) What is the resistance of the music system. (ii) The music system is left playing for several hours and finally the battery voltage drops and the music system stops when the current drops to 320mA. At what battery voltage does the music system stops playing.(2 Marks) (b) Calculate the quantity of heat produced in a 20 ohm resistor carrying 2.5 A current in 5 minutes. (2 Marks) SOLUTION: (a) (b) Q6.(a) The VI graph for a series combination and for a parallel combination of two resistors is shown in the figure below. Which of the two A or B, represents the parallel combination? Give a reason for your answer.( 2 Marks) (b) State the characteristics required in a material to be used as an effective fuse wire.( 2 Marks) (c) Which coil of a step up transformer is made thicker and why?( 2 Marks) SOLUTION: (a) A represent parallel combination because A is less steeper than B , so resistance of A is less than B . As we know resistance in parallel combination is less than series combination. SOLUTION: (b) The material to be used as a fuse wire should have high resistivity and low melting 1 point. (c) The thicker wire is used in a primary coil because more current flows in primary coil than secondary coil. Q7.A battery of emf 12V and internal resistance 2 are connected with 2 resistors A and B of resistance 4 and 6 respectively joined in series. Find (i) Current in the circuit (ii) The terminal voltage of the cell. (iii) The potential difference across 6 resistor. (iv) Electrical energy spent per minute in 4 resistor. (4 Marks) SOLUTION: SOLUTION: Q8.(i) Name the device used to increase the voltage at a generating station. (ii) At what frequency is AC supplied to residential houses. (iii) Name the wire in a household electrical circuit to which switch is connected.(3 Marks) SOLUTION: (i) Transformer (ii) 50 Hz (iii) Live wire Reach out to me @ k.abhishek@vedantu.com
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