Science Class 7th

431. In a circuit, resistance decreases as more resistors are added.

A) Parallel

B) Series

C) None

432. Ohm’s law shows relationship between?

A) Voltage

B) Current

C) Resistance

D) All of these

433.____ is a device used to measure the amount of current an electric circuit.

A) Scale

B) Ammeter

C) Tester

D) None

534. An ammeter has very resistance.

A) High

B) Low

C) None

435. Voltage or potential difference between two points is measured by?

A) Ammeter

B) Scale

C) Voltmeter

D) None

636. Ammeter is connected in ____ in a circuit.

A) Series

B) Parallel

C) None

437. Which of the following has high resistance?

A) Ammeter

B) Voltmeter

C) None of these

438. Which is large unit of energy?

A) Watt

B) Kilowatt hour

C) None

439. ____ is the energy used by a device at a rate of 1000 watts in one hour.

A) Kilowatt hour

B) Watt

C) Both ‘a’ and ‘b’

D) None

440. 1 kWh is equal to Joules.

A) 500000

B) 600000

C) 3600000

441. The main cable through which electricity is supplied to houses contains?

A) Neutral Wire

B) Live Wire

C) Both ‘a’ and ‘b’

D) None

442. A ___ are fitted in the path of live wire.

A) Main wire switch

B) Main circuit breaker

C) Both ‘a’ and ‘b’

D) None

443. To avoid the risk of electric shocks, the metal body of an electrical appliance is?

A) Wired

B) Neutralised

C) Earthed

D) None

444. The wire used in earthing is called?

A) Earth wire

B) Wire

C) Circuit breaker

D) None

445. Thin wire of tin or tin-lead alloy used in fuse has melting point.

A) Low

B) High

C) None

446. Fuse breaks circuit and melts when current exceeds value.

A) Safe

B) Dangerous

C) None

447. Fuse works on the ___ effect of current.

A) Chemical

B) Heating

C) None

448. A fuse wire is connected in to electrical circuit.

A) Series

B) Parallel

449. Which can’t be used as a fuse wire?

A) Tin

B) Tin-lead

C) Copper

D) None

450. Which ensures safe supply of electricity to appliances and reduce chances of electric shocks?

A) Fuse

B) Three pin plugs

C) None