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5 bulbs are connected in series in a room. One bulb is fused. It is removed and remaining 4 bulbs are again connected in series to the same circuit. What will be the effect on the following physical quantities? (Increases, Decreases, Remain Same). |
- Resistance
- Intensity of light
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Rohan conducted experiments on echo in different media. He observed that a minimum distance of 'x' meters is required for the echo to be heard in oxygen and 'y' meters in benzene. Compare 'x' and 'y'. Justify your answer.
Speed of sound in oxygen: 340 ms-1
Speed of sound in benzene: 200 ms-1
Concept: undefined >> undefined
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Below is an incomplete table showing the arrangement of electromagnetic spectrum in the increasing order of their wavelength. Complete the table:
| Gamma ray | X - ray | UV rays | Visible rays | Infrared | A | Radio waves |
- Identify the radiation A.
- Name the radiation used to detect fracture in bones.
- Name one property common to both A and Radio waves.
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Light travels a distance of '10x' units in time 't1' in vacuum and it travels a distance of 'x' units in time 't2' in a denser medium. Using this information answer the question that follows:
'Light covers a distance of '20x' units in time 't1' in diamond'. State true or false.
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Name one radiation having the wavelength longer than the wavelength of these radiations.
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For the following scenario, state whether the work done by gravity is positive, negative, or zero.
A person walks on a levelled road.
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For the following scenario, state whether the work done by gravity is positive, negative, or zero.
A person climbs a ladder.
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For the following scenario, state whether the work done by gravity is positive, negative, or zero.
A car in neutral gear is coming down the slope.
Concept: undefined >> undefined
Observe the given circuit diagram and answer the questions that follow:

- Calculate the resistance of the circuit when the key K completes the circuit.
- Calculate the current through 3Ω resistance when the circuit is complete.
Concept: undefined >> undefined
A man raises a box of mass 50 kg to a height of 2 m in 20 s, while another man raises the same box to the same height in 50 s. Compare:
- the work done, and
- the power developed by them. Take g = 10 N kg-1
Concept: undefined >> undefined
A boy weighing 50 kgf climbs up from the first floor at a height of 3 m above the ground to the third floor at a height of 9 m above the ground. What will be the increase in his gravitational potential energy? (Take g = 10 N kg-1).
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Name two electromagnetic waves of wavelength smaller than that of violet light.
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Define the term resistance.
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Two copper wires are of the same length, but one is thicker than the other. Which wire will have more specific resistance?
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Name the material of fuse. State one characteristic of the material used for fuse.
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State the purpose of using a fuse in a circuit.
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How does the length of a fuse wire depend on its current rating?
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Two fuse wires are rated 5 A and 20 A. Which of the two is longer ?
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'A fuse is rated 8 A'. Can it be used with an electrical appliance of rating 5 kW, 200 V?
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Name two safety devices which are connected to the live wire of a household electric circuit.
Concept: undefined >> undefined
