MEDHA_ROUND1

Who witnessed the effect of magnetism for the first time?

• Hans Christian Oersted
  
  

• ) Alexander Graham Bell

• Michael Faraday

• Gustav Robert Kirchhoff

What does positive power in an electrical element indicate?

• Element is absorbing power
  
  

• Element is supplying power
  
  

• Element may absorb or supply power
  
  

• Element is neither absorbing nor supplying power

Which was the India’s first electrified city?

• . Chandigarh

• . Darjeeling

• Indore

• Ahmadabad

If a friend receives a severe electric shock from an electrical appliance in your home, what should your first response be?

• Grab the appliance and throw it aside so that you can tend to your friend

• Run to the circuit breaker and turn off the main switch.
  
  

• Use a wooden broomstick to push the appliance away safely.

• BOTH B AND C

What does the term “overloading” mean in electrical safety?

• Using too many electrical devices simultaneously
  
  

• Using energy-efficient appliances
  
  

• Overcharging a battery
  
  

• Insulating electrical wires

Two bulbs,one 250V 100W and second 250v,25w are connected in series and 44Ov ac 50 Hz is applied across the two bulbs. Which of the following will happen

• 100W bulb glows bright compare to 25W bulb

• ) Both 100W bulb and 25w bulb will glow normal

• ) 25w bulb will burn-out

• 25W bulb glows bright compare to 100W bulb

A constant voltage is applied between two ends of a metallic wire. If the length is halved and the radius of the wire is doubled, the rate of heat developed in the wire will be

• Increased 8 times

• Unchanged

• Doubled

• Halved

. A uniform wire of length l and radius r has a resistance of 100 Ω. It is recast into a wire of radius r/2.The resistance of new wire will be

• 400 Ω

• 100 Ω

• 200

• 1600

. A 2 W carbon resistor is colour coded with green, black, red and brown, respectively. The maximum current which can be passed through this resistor is

• 20mA

• 0.4mA

• 100 mA

• 200mA

. Of the two bulbs,one glows brighter than the other.Which bulb has a higher resistance (connecting the two bulbs one by one with the same voltage source,not togeteher)?

• Brightness is independent of resistance

• The bright bulb

• ) Both have the same resistances

• the dim bulb