An object is at a temperature of 400° C . At what temperature would it radiate energy twice as fast? The temperature of the surroundings may be assumed to be negligible

Question

An object is at a temperature of 400° C . At what temperature would it radiate energy twice as fast? The temperature of the surroundings may be assumed to be negligible (A)  200° C  (B) 200 K (C)  800° C  (D) 800 K

Tardigrade Admin · Accepted Answer

In first state, E=σ (673)4 In second state, 2E=σ T4 ∴ (1/2)=( (673/T) )4 T=(2)1/4× 673=800 K

Q. An object is at a temperature of $400^{\circ} C$ . At what temperature would it radiate energy twice as fast? The temperature of the surroundings may be assumed to be negligible

$200^{\circ} C$

200 K

$800^{\circ} C$

$800 K$

In first state, $E = σ (673)^{4}$ In second state, $2 E = σ T^{4}$ $∴$ $\frac{1}{2} = (\frac{673}{T})^{4}$ $T = (2)^{1/4} \times 673 = 800 K$

Q. An object is at a temperature of 400∘C . At what temperature would it radiate energy twice as fast? The temperature of the surroundings may be assumed to be negligible

200∘C

200 K

800∘C

800K

In first state, E=σ(673)4 In second state, 2E=σT4 ∴ 21​=(T673​)4 T=(2)1/4×673=800K

Q. An object is at a temperature of $400^{\circ} C$ . At what temperature would it radiate energy twice as fast? The temperature of the surroundings may be assumed to be negligible

$200^{\circ} C$

$800^{\circ} C$

$800 K$

In first state, $E = σ (673)^{4}$ In second state, $2 E = σ T^{4}$ $∴$ $\frac{1}{2} = (\frac{673}{T})^{4}$ $T = (2)^{1/4} \times 673 = 800 K$